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Open Access
A COMPARATIVE STUDY ON CYTOGENETIC PROFILE OF CROSSBRED AND INDIGENOUS PIGS
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2017-02) HARSHINI, V; SAKUNTHALA DEVI, K(MAJOR); PUNYA KUMARI, B; SURESH, J
ABSTRACT: The present analysis was carried out on 30 blood samples of LWY crossbred pigs (15 females and 15 males) maintained at All India Coordinated Research Project on pig (AICRP), College of Veterinary Science, Tirupati, Chittor District of Andhra Pradesh and on 30 blood samples of indigenous pigs (15 females and 15 males) maintained by the farmers in and around Tirupati to study the cytogenetic profile of both the breeds and their morphometric measurements using short term leukocyte culture technique. The diploid chromosome number (2n) in both the breeds was 38 with XX and XY complement in females and males respectively and a fundamental number of 64 as in exotic pigs. Among 18 pairs of autosomes, first 5 pairs were sub-metacentric followed by 6th and 7th pair as sub-telocentric, next 5 pairs (8th to 12th pairs) were metacentric and remaining six pairs (13th to 18th) were telocentric. Among these one pair of allosomes i.e. X-chromosome was large metacentric, while Y-chromosome was metacentric and smallest chromosome of the karyotype. The least squares mean relative length of autosomes in LWY crossbred pigs ranged from 2.79±0.02 to 10.83±0.05 in females and 2.81±0.05 to 10.87±0.07 in males. The least squares mean relative length values for non-descript pigs ranged from 2.84±0.03 to 11.01±0.07 in females and 2.86±0.03 to 11.04±0.05 in males. The relative contribution of X-chromosome in LWY crossbred female and male pig was 4.67±0.01 and 4.65±0.04, whereas the values were 4.82±0.03 and 4.80±0.04 in non-descript pigs respectively. The mean relative contribution of Y-chromosome were 2.05±0.10 and 2.19±0.13 in LWY crossbred and non-descript pigs respectively. Genetic group had significant effect on the relative length of all autosomes and allosomes except 17th and 18th chromosomes, whereas sex had no significant effect on relative length of all chromosomes in both the breeds. The overall mean arm ratio of 12 pairs of autosomes ranged from 1.01±0.03 to 2.45±0.03 and 1.02±0.01 to 2.43±0.02 in LWY crossbred females and males respectively, whereas these values varied from 1.03±0.02 to 2.51±0.06 in females and 1.04±0.06 to 2.52±0.03 in males of non-descript pigs. The mean arm ratio values of X-chromosome was 1.15±0.04 in females and 1.13±0.03 in males of LWY crossbred pigs, while the respective mean values in non-descript pigs were 1.14±0.03 and 1.12±0.03 respectively. The arm ratio values of Y-chromosome were 1.17±0.02 and 1.18±0.02 in LWY crossbred and non-descript pigs. The mean centromeric indices of autosomes (1 to 12 pairs) differed from 0.50±0.04 to 0.71±0.02 and 0.52±0.03 to 0.72±0.03 in LWY crossbred female and male pigs, whereas it ranged from 0.51±0.01 to 0.82±0.01 and 0.53±0.05 to 0.83±0.02 respectively in non-descript pigs. The X-chromosome had mean centromeric index values of 0.53±0.03 and 0.52±0.03 in LWY crossbred female and male pigs, while the value for Y-chromosome was 0.56±0.02. The mean centromeric index values of X-chromosome in non-descript pigs were 0.52±0.02 and 0.54±0.02 in females and males, whereas for Y-chromosome, it was recorded as 0.55±0.01 respectively. The average morphological index value of autosomes ranged from 2.43±0.06 to 7.29±0.11 in females and 2.41±0.05 to 7.31±0.12 in males of LWY crossbred pigs, while X-chromosome had 5.85±0.05 and 5.84±0.05 respectively. The mean values for autosomes ranged in non-descript pigs were 2.42±0.02 to 7.96±0.14 and 2.44±0.04 to 7.98±0.13 in females and males, whereas X-chromosome had an index value 6.01±0.02 and 5.99±0.03 respectively. The values for Y-chromosome were 2.01±0.02 and 2.09±0.01 in LWY crossbred and non-descript pigs. In the present investigation with 128 metaphase spreads, a total of 311 NORs were detected in LWY crossbred and non-descript pigs. The mean number of NORs per metaphase was 2.67 and 2.20 in both breeds respectively. The highest frequency of metaphases (47.61% and 81.54%) had 2 number of NORs, whereas lowest frequency of metaphases (7.94% and 3.07%) had 4 number of NORs. The percentage share of silver deposits on 10th pair of chromosome accounts for 96.67 and 68.33 in LWY crossbred and non-descript pigs, whereas on 8th chromosome pair the percentage share of deposits were 44.16 and 51.67 respectively. The outcome of present study have revealed that the morphology, number and various morphometric measurements of the chromosomes in both the breeds were analogous to those reported in literature for various pig breeds like Canadian Lacombe, Landrace, Duroc, Thai wild boar, Nigerian indigenous pig, Niang Megha pig, Korean native pig, Polish Landrace, Hampshire, Large White Yorkshire, Turkish sus scrofa. Therefore, the efforts should be undertaken to recognize the non-descript pigs as a distinct breed of Andhra Pradesh.
Open Access
A STUDY ON MORPHOLOGICAL AND GENETIC VARIATION IN NELLORE PALLA SHEEP
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2017-01) SAI HARINI, K; Punya kumara, B(MAJOR); Vinoo, R; Suresh Babu, D
ABSTRACT: The southern peninsular region of India is home to fourteen descriptive mutton breeds, of which Nellore is the country's tallest sheep, predominantly distributed in areas of Nellore and Prakasam districts of Andhra Pradesh. Based on coat colour three varieties were seen: Jodipi, Brown (Dora) and Palla. Nellore Jodipi is predominant in its population followed by Brown and Palla. Nellore palla sheep are confined to only certain areas of Nellore district and very scanty information is available on the performance of the breed. The population of Nellore Palla is under threat (<1500). Hence, genetic and phenotypic evaluation of the breed is important not only from conservation point of view, but also to assess the level of inbreeding in the population. The present study was carried out to figure out productive and reproductive performance in Nellore Palla sheep under field conditions and also to assess the genetic structure of Nellore Palla sheep at molecular level using twenty four microsatellite markers recommended by ISAG/FAO for genetic diversity studies in sheep. A total of 347 sheep of different age groups were used to study the morphometric measurements of Nellore palla sheep and 50 blood samples from unrelated sheep flocks were used for molecular studies. The overall least squares means of body weights (kg), height at withers, chest girth, paunch girth and body length were 35.18 ± 0.27, 78.47 ± 1.55, 80.82 ± 0.66, 80.93 ± 1.37 and 69.90 ± 0.83 at 2- teeth age, 39.65 ± 0.33, 82.45 ± 0.98, 84.57 ± 0.72, 84.11 ± 1.34 and 72.23 ± 1.02 at 4- teeth age, 41.18 ± 0.56, 83.63 ± 0.64, 86.32 ± 0.74, 85.88 ± 1.23 and 74.55 ± 0.81 at 6- teeth age, 45.00 ± 0.46, 85.22 ± 1.97, 87.17 ± 0.58, 86.14 ± 0.52 and 76.17 ± 0.33 at 8- teeth of age respectively. Villages and sex showed a significant (p<0.01) effect at all ages and the parameters studied. The overall least squares means of age at first mating in males, age at first mating in females, age at first lambing, tupping and lambing percentages were 598.03 ± 3.02 days, 361.54 ± 1.09 days, 509.32 ± 1.00 days, 81.06 ± 1.61 and 73.37 ± 1.53 percent, respectively. The coefficient of correlations between body weights with the height at withers, chest girth, paunch girth and body length varied from 0.58(PG) to 1.00(CG) in males and 0.16(PG) to 0.69(HW) in females. A perfect phonotypic correlation (1.00) was observed for body weights and height at withers at in 8- teeth age males and for body weights and chest girth for males at 6- teeth age. All the correlations were positive and highly significant (p<0.01) in majority of the age groups studied. The standard Phenol-Chloroform method was used for isolation of DNA from 50 blood samples. The quality and quantity of DNA was checked by agarose gel electrophoresis and Nanodrop spectrophotometer, respectively. The allele frequencies, observed number of alleles (Na), effective number of alleles (Ne), observed (Ho) and expected (He) heterozygosity, within population inbreeding estimates (FIS) were computed using POPGENE32 software. A total of 189 alleles were found across the 24 microsatellite loci studied. The number of alleles at each locus ranged from five (BM6506, CSSM31 and HUJ616) to a maximum of thirteen (BM827 and OARHH64) with a mean of 7.8 alleles across all loci. The allele sizes ranged from a minimum of 81 bp (OarJMP8) to a maximum of 258 bp in MAF214, while, the allele frequencies ranged from a minimum of 0.010 (BM827, INRA63, OarFCB48 and OarHH64) to a maximum of 0.40 (OarFCB128). The mean effective number of alleles was 6.6452 ± 0.3933 which was less than the observed number of alleles and ranged from 3.4916 (CSSM31) to 11.574 (BM827). The observed heterozygosity (Ho) and expected heterozygosity (He) ranged from 0.00 (BM1314, BM6506, BM8125, HUJ616, OARCP20, OARFCB128, OARJMP8) to 0.16 (OARHH64) and from 0.7208 (CSSM31) to 0.9228 (BM827) with an overall value of 0.0626 ± 0.010 and 0.8361 ± 0.009, respectively. All the twenty four microsatellite loci were found to be highly polymorphic and the PIC values ranged from 0.6616 (CSSM31) to 0.9136 (BM827) with a mean of 0.8171. The FIS values were found positive and ranged from 0.8201 (OARHH64) to 1.000 (BM1314, BM6506, BM8125, HUJ616, OARCP20, OARFCB128, OARJMP8). The mean FIS value across the twenty four loci observed was 0.9257. The χ2 test revealed that all the twenty four loci deviated significantly from Hardy- Weinberg Equilibrium.
Open Access
ASSESSMENT OF GENETIC DIVERSITY IN ONGOLE AND PUNGANUR CATTLE BREEDS THROUGH MICROSATELLITE TYPING
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2013-04) ASHA, UPPUTURI; Sakunthala Devi, K(MAJOR); Rajkumar, U; Harikrishna, Ch
ABSTRACT: Twenty dinucleotide microsatellite markers viz ETHOLO, ILSTSOOS, TGLA122, INRA035, INRA063, HEL001, TGLA 126, INRAOOS, ILSTS006, INRA032, ETH225, CSRM060, BMI 824, TGLA053, INRAO37, ETHO03, TGLA227, MM012, HAUT024 and HAUT027 were used for Assessment of genetic diversity in Ongole and Punganur cattle breeds through Microsatellite typing. The mean quantity of DNA was 2.96 pdml in Ongole and 3.16 pg/ml in Punganur cattle. Mean optical absorbance ratio (2601280nm) was 1.78 in both Ongole and Punganur cattle indicating good quality of genomic DNA. Out of the total 216 alleles detected, 98 alleles were specific to Ongole and 75 alleles were specific to Punganur. Mean number of alleles obtained at each locus varied from 1 to 12 in Ongole and 1 to 13 in Punganur cattle. The overall mean effective number of alleles was found to be 4.09 in Ongole and 3.41 in Punganur cattle. The overall mean expected heterozygosity and observed heterozygosity were 0.65 and 0.33 in Ongole and 0.55 and 0.3 1 in Punganur breed, respectively. The overall mean PIC values observed were 0.62 and 0.53 in Ongole and Punganur breeds respectively. The mean inbreeding coefficient (Fls) obtained in the present study was 0.456 for Ongole and 0.434 in Punganur breed. F-statistics revealed moderate inbreeding within the breeds and existence of moderate relationship between the Ongole and Punganur cattle. In Ongole population, loci ETHO10, TGLA122, INRA035, INRA063, HEL001, ILSTS006, TGLA126, ETH225, CSRM60, TGLA053, INRA037, ETH003, MM012, HAUT027 and HAUT024 were deviated significantly from the equilibrium frequency (I'c0.01). In Punganur breed, except the locus TGLA126, ETH225 and CSRMO60, all other loci deviated significantly (Ps0.01) from the Hardy-Weinberg equilibrium.
Open Access
GENETIC ANALYSIS OF PRODUCTIVE AND REPRODUCTIVE PERFORMANCE IN CROSSBRED PIGS
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2010-07) PANDU RANGA REDDY, P; PUNYA KUMARI, B(MAJOR); GNANA PRAKASH, M; SURESH, J
ABSTRACT: Data on 1662 pigs belonging to 50 and 75% Large White Yorkshire (LWY)-desi crossbreds maintained at All India Coordinated Research Project on Pigs, Tirupati born during 2005 to 2010 were utilizd to study the influenct of genetic and non-gcnctic factors on reproductive traits, litter traits, body weights, body measurements and avcrage daily gains. Prediction equations were developed to cstirnatc body weights based on body meanmments. Genetic parameters were estimated for various traits. The overall least squares means for AFS, AFF, FL GP and SP were 329.05 * 2.90, 440.42 * 2.80, 171.15 ~t 2.97, 111.28 zt 0.26 and 283.87 * 3.00 days respectively. The effects of pcriod and stason only were significant on reproductive baits. The overall kast quarts mean LSB, LSW and LWB and LWW were 7.59 * 0.17, 6.94 0.16 piglets and 8.40 + 0.18 and 66.92 * 1.42 kg, respectively. The effects of pcriod and parity were significant (Pg.O1) on majority of the litter traits. The overall least squares mcan body weights were 1.13 * 0.02, 2.13 It 0.01, 3.19 * 0.02, 4.29 * 0.02, 5.41 It 0.03, 6.48 0.03, 7.55 * 0.04, 8.72 * 0.05 and 9.97 * 0.06 kg at birth, 1, 2, 3, 4, 5, 6, 7 and 8 wks of age, respectively. Genetic group, period, parity and litter size pup affected all pre weaning body weights highly significantly except for the non-significant effect of stason on body weight at birth. Scxual dimorphism in favour of males was evident from 1 to 6 weeks of age. Body weights of piglets born in rainy and winter seasons and those from smaller litters recorded significantly higher body weights. The overall least squares means for BL, HW. HG and PG varied from 22.68 to 50.58, 16.91 to 36.65, 23.27 to 47.43, 19.03 to 42.19 cm from bid to 8 weeks of age. The effect of litter size group was significant on all the biomctrical measurements at various ages. Season also influenced body measurements at birth, 2 and 8 weeks of age significantly where as at other ages it influmced one (or) more traits but not all. Parity e f f i was significant on all the body measurements at 4 and 6 weeks of age. Sexual dimorphism was evident on all the body measurements at birth only. Significant effect of genetic group was observed only on heart girth and paunch girth at birth and 2 woeks of age, respectively. The overall least squares mean ADG during 0 to 2, 2 to 4, 4 to 6, 6 to 8 and birth to 8 weeks wm 0.150 + 0.001, 0.160 f 0.001, 0.150 * 0.002, 0.170 * 0.002 and 0.160 * 0.001 kg, respectively. Pigs from smaller litters recorded significantly higher ADGs. Heritability of gestation period in 75% LWY group was 0.08 * 0.38 while that of litter traits ranged hm 0.14 + 0.35 to 0.32 + 0.48 among the genetic groups. Heritability estimates varied from 0.19 + 0.09 to 0.97 * 0.22 for body weights and from 0.13 * 0.08 to 0.80 f 0.17 for ADGs. Heritability estimates among body measurements were medium to high. The genetic, phenotypic and environmental correlations among gestation period and litter traits ranged hm -0.76 to 029, -0.24 to 0.01 and -0.22 to 0.35, while those among litter baits wm all positive and high. Genetic, phenotypic and environmental correlations among body weights were positive and medium to high. Phenotypic comlations among body weights were all positive. Comlations among ADGs were very low without any consistent trend. Phenotypic correlations among body measurements ranged from - 0.0 1 to 0.9 1 and among body weights and measurements, it ranged from -0.03 to 0.86. Prediction equations were developed to predict body weight at birth 2, 4, 6 and 8 weeks of age based on cOrnSponding measurements on each genetic group. The R~ values varied from 69.1 to 81.7 percent among the genetic groups. Multiple regression equations developed at 2 and 8 weeks of age were found to be most efficient of all.
Open Access
CYTOGENETIC CHARACTERIZATION OF MAHABUBNAGAR GOATS
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2010-07) UMA DEVI, P; Ramesh Gupta, P(MAJOR); Sakunthala Devi, K; Dhana Lakshmi, K
ABSTRACT : The research was carried out on Mahabubnagar (34) and non-descript goats (13) for cytogenetic characterization by the short term lymphocyte culture technique. A total of 1050 metaphase spreads were examined for the chromosome count and morphology and for Mahabubnagar goats 170 karyotypes and for non-descript animals 75 karyotypes of were prepared. The diploid chromosome number in all the goats was found to be 2n = 60, XY in males and 2n = 60, XX in females. All the autosomes were acrocentric in morphology. The X-chromosome was the longest acrocentric, while the Y-chromosome was smallest and dot-like in appearance in majority of the karyotypes examined. In few metaphase spreads, it was submetacentric in appearance. The data on relative length were converted into angles using arcsin transformation for conducting the least squares analysis. The variation in relative length of the chromosomes was not significant between animals in Mahabubnagar goats, while it was significant for the autosomes 1 to 11 and 19 to 29 in non-descript goats. The effect of genetic group, sex of the animal, coat color and presence or absence of horns, beard and wattles on relative length of the chromosomes was found to be non-significant. The overall least squares mean relative length of autosomes, X- and Y-chromosomes varied from 2.029 to 4.825 percent, 5.164 and 1.961 percent respectively. Among the genetic groups, sexes, coat colours and presence or absence of horns, beard and wattles the least squares means for relative length ranged from 1.975 to 4.937, 1.922 to 4.828, 2.041 to 5.065, 1.982 to 4.856, 1.985 to 4.915 and 1.950 to 5.042 percent, respectively for autosomes and for the X-chromosome ranged from 5.010 to 5.320, 5.147 to 5.181, 4.984 to 5.405, 5.105 to 5.224, 5.104 to 5.224 and 4.944 to 5.388 percent, respectively. The contribution of Y-chromosome to the total genome was 0.457 and 0.509 percent in Mahabubnagar and non-descript goats, respectively. The Y-chromosome overall mean arm ratio, centromeric index and morphological indices were 1.68, 39.22 percent and 214.00, respectively, confirming its submetacentric morphology. In the present investigation with 42 metaphase spreads, a total of 213 NORs were detected in Mahabubnagar goats. The mean number of NORs per metaphase was 5.071, which ranged from 4.72 to 6.17, where as the number of NORs per metaphase ranged from 1 to 13. The highest frequency (P<0.05) of metaphases (21.43%) examined had one NOR, while the lowest frequency (2.38%) had 9 or 11 NORs. The outcome of the present study have revealed that the morphology, number and various morphometric measurements of the chromosomes of the Mahabubnagar goats were analogous to those reported in literature for descript breeds of goats in India like Bengal, Pashmina, Gaddi and local goats like Kanni Adu of Tamil Nadu and local goats of Rohilkhand region. Therefore, the Mahabubnagar goats may be recognized as a distinct breed of Andhra Pradesh State.
Open Access
CYTOGENETIC CHARACTERIZATION OF PUNGANUR CATTLE
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2010-07) BHARATHI, GUTTI; SAKARAM, D(MAJOR); RAMESH GUPTA, B; RAGHUNANDAN, T
ABSTRACT : The blood samples of total 30 animals consisting each sex of 15 animals of Punganur and 5 ND animals(2M+3F) were cultured through short term lymphocyte method and 1000 metaphases of these animals were analyzed for morphology and different morphometric aspects for characterization. The diploid chromosome number consisting of 60 (2n=60, XY) was found in both the cattle. All the autosomes were acrocentric. X-chromosome was sub-metacentric while the Y- was found smallest acrocentric. The morphometry revealed that mean relative lengths of autosomes varied from 5.34 to 1.87 percent in Punganur and 5.10 to 1.97 percent in ND. The X-chromosome contributed 4.81 and 4.57 percent in Punganur and ND, while the Y-chromosome accounted 1.69 and 1.93 percent in Punganur and ND to Genome. The means for arm ratio, centromeric index and morphological index of the X- chromosome were 1.55± 0.17, 0.40±0.05 and 5.12±0.46 in Punganur and 1.55±0.05, 0.40±0.01 and 5.30±0.29 in ND respectively. Analysis of variance based on the transformed relative lengths revealed significant differences among the genetic groups with respect to the relative lengths of chromosomes 10, 26, 27, 28, 29, and Y-chromosome. The relative lengths of all chromosome except 9, 10, 11, 12, 13, 14, 28, 29 and X-chromosome showed differences among sexes in Punganur cattle. The sex wise analysis of variance in ND cattle revealed no significant difference among the sexes for all chromosomes except 29 pair of autosome. The NOR-banding revealed that on average 5 chromosomes in the complement showed the NOR regions most of them present on telomeres and some of them are in ends of the long arms. Even though the location and distribution of these regions varies among breeds of cattle, the NOR pertaining to this breed were located on chromosomes 2, 3, 4, 5 and 28.
Open Access
CYTOGENETIC STUDIES ON ONGOLE BREED OF CATTLE
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2010-07) BHARATI, ALOK; GNANA PRAKASH, M(MAJOR); SAKARAM, D; NARASIMHA REDDY, Y
ABSTRACT: A cytogcnctic study was conducted on 38 Ongole cattle maintained at Livestock Research Station, Lam. Ciuntur and nearby villages by utilizing shortterm lymphocyte culture technique. The normal diploid chromoso~nen umber was 60 which consisted of 29 pairs of acrocentric autosomes and one pair of sex chromosomes. The X-chromoson~e was sub-mctnccntric and Y clirolnosome \vils acrocentric. The ~norphometric measurements of clir.o~nosorncs obtained li.0111 farm bred aninials and those from ficld animals clid not diffr signific:lntly. l'he relative lengths (RL) of chrornoso~ncs I, 5, 6, 15, 16, 17, 15, 23, 24, 25, 26, 27, 28, 29 and X clwomosome were significantly different anlong the sexes. The RL of autosolnes ranged from 1.92 + 0.01 to 5.24 * 0.02 per cent. The Xchromosome was the longest while Y-chi-ornosome was the shortest and contributed 5.42 + 0.03 and 1.79 + 0.02 per cent to the genome. The decline in the RL of the chromosomes was sha1-p lio~lI ~to 3 and was gradual thercaficr. The arm ratio, ccnt~x~meriicn dex and moi.phological intlcv fbr thc X-chromosome were 1.87 + 0.015, 0.35 * 0.002 ant1 5.75 + 0.075, respectively.
Open Access
ANALYSIS OF POLYMORPHISM AT THE TNF-α AND PGR LOCI AND THEIR ASSOCIATION WITH REPRODUCTIVE TRAITS IN ONGOLE CATTLE
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2018-01) NAGA SHIVA KUMAR, KONAPALLI; MURALIDHAR, M(MAJOR); SUDHAKAR, K; VENKATA NAIDU, G
ABSTRACT: The present study was aimed at understanding genetic polymorphism at two loci namely Tumour Necrosis Factor-α (TNF-) and Progesterone receptor (PGR) genes in Ongole cattle using PCR-RFLP method. Two Single Nucleotide Polymorphisms (SNPs) were analysed, one for each locus. Primers were designed to amplify the targeted SNP of both the genes. DNA samples from a total of 150 Ongole cattle breed were used in the present study. The amplicons of TNF-α were subjected to RFLP with RsaI restriction enzyme and the PGR amplicons with DraIII enzyme. Based on RFLP profile obtained, the genotypic and allelic frequencies were determined for the targeted SNP. In the present study the PGR gene was monomorphic in all the samples. The TNF-α gene was polymorphic, only two genotypes G/G and G/A were observed. No individual in the present study was homozygous for the allele A at this locus. The G/G genotype is predominant in Ongole population with a frequency of 0.74 followed by G/A genotype with 0.36. The major allele in this locus in Ongole population is G and the minor allele is A with a frequency of 0.13. The Ongole population at this SNP locus is under equilibrium in the present study. Association analysis with the phenotypes that indicate reproductive performance parameters namely, calving interval, service period and dry period with the available data indicated no significant association between the genotype and any of these traits. Further studies with more information are required to understand precise role of the SNP in gene regulation and function
Open Access
GENETIC DIVERGENCE OF VIZIANAGARAM AND MACHERLA BROWN SHEEP WITH NELLORE SHEEP: A STUDY
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2018-01) TEJASWANI, VENNELA; VINOO, R(MAJOR); SUDHAKAR, K; VENKATA SESHAIAH, Ch
ABSTRACT : In India, most of the small and marginal farmers depend on sheep for their livelihood for which reason, they are considered as an important small ruminant. Several sheep breeds like Nellore and Deccani have been reared in different places of Andhra Pradesh for the past few decades and showing marginal gain to the shepherd community. Apart from these two characterized breeds, there are two other local genetic groups viz. Vizianagaram and Macherla Brown sheep reared by local shepherds. The Vizianagaram sheep are distributed in the North coastal region of Andhra Pradesh whereas Macherla Brown sheep are distributed in the villages adjacent to Krishna river in Guntur, Prakasam and Krishna districts. These two genetic groups of sheep are yet to be characterized and the genetic distances with other breeds is to be established. Phenotypic and production performances indicate that these two genetic groups are different from Nellore sheep. The objective of the present research is to study the genetic variation in the three genetic groups of Andhra Pradesh and their phylogenetic status using mitochondrial DNA control region. Blood samples were collected from six Macherla and Vizianagaram sheep respectively. Genomic DNA was isolated and 885 bp mitochondrial control region was amplified and sequenced. Metadata of Nellore and other Indian breeds were obtained from NCBI database and total of 341 sequences were aligned and trimmed to have a final length of 721 bp. The measures like polymorphism, divergence, gene flow and genetic differentiation were estimated using DnaSP software. A phylogenetic tree was constructed using Neighbour joining method by MEGA software. The tree topology was tested using 1000 bootstrap replications. The results of polymorphism and divergence analysis disclosed the existence of polymorphism in three genetic groups of Andhra Pradesh and these genetic groups were distinct. The findings of gene flow and genetic differentiation estimates concluded the presence of high differentiation and moderate sub-structuring of the three genetic groups in Andhra Pradesh similar to other sheep breeds in India. The phylogenetic analysis indicated that, all the haplotypes of the two genetic groups of sheep (Vizianagaram and Macherla) under present study are in lineage A along with majority of the other Indian sheep breeds. In Nellore sheep, out of 28 haplotypes, 26 were grouped in lineage A and 2 were grouped in lineage B. This separation could be due to the existing hypothesis that there may be two independent domestication events in India.

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