• Asian-Australasian Journal of Animal Sciences
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• v.23 no.7
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• pp.863-866
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• 2010

Myostatin, which is also known as growth and differentiation factor 8 (GDF8), has been reported to act as a negative regulator of skeletal muscle development. Variation in the myostatin gene (MSTN) has been associated with variation in muscularity in certain "meaty" sheep breeds. Polymerase Chain Reaction-Single Strand Conformational Polymorphism (PCR-SSCP) analysis was used to investigate allelic variation in the previously described g+6223G>A single-nucleotide polymorphism (SNP) in the 3' untranslated region (3' UTR) of MSTN. The sheep studied were 79 New Zealand (NZ) Romney lambs derived from a single sire heterozyous for g+6223G>A, which is in itself notable as this polymorphism has not been described previously in this breed. Allelic variation was observed to be associated with an abnormal gender ratio (p = 0.046) in the progeny. The presence of allele A was observed to have an effect (p<0.05) on birth weight, mean loin yield, proportion yield loin and total muscle yield. Allelic variation did not significantly affect mean shoulder yield, leg yield, proportion yield shoulder and proportion yield leg. This preliminary result suggests that while the A allele at MSTN g+6223 appears to improve some valuable traits in NZ Romney sheep, further research is required to understand if and how it may affect other traits.

• Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.151-155
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• 2012

We used nine microsatellite DNA markers to estimate genetic variation among wild and cultured populations of the sea squirt Halocynthia roretzi. The loci were polymorphic, with 6-32 alleles, and allelic richness ranged from 6.0 to 26.1 in each population. The wild and the cultured populations had similar mean heterozygosities ($H_O$ and $H_E$), allele numbers, and allelic richness. One cultured population with softness syndrome had a lower mean in the observed heterozygosity ($H_O$ = 0.57) and higher mean inbreeding coefficient ($F_{IS}$ = 0.261) than any other populations. This suggests that the loss of genetic variation in the diseased population might be due to increased inbreeding. A neighbor-joining tree and pairwise population estimates of $F_{ST}$ showed moderate genetic differentiation between the wild and the cultured populations. Additionally, the softness syndrome population was genetically divergent from wild populations, but it was genetically close to the cultured populations.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1487-1494
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• 2009

The major histocompatibility complex (MHC) plays well-defined roles in eliciting immune responses and combating infectious diseases. The major histocompatibility complex of cattle is referred to as BoLA (Bovine Lymphocyte Antigen). This genetic system is among the most polymorphic. In the present study, polymorphism of the BoLA- DRB3.2 locus in three Bos indicus breeds viz., Sahiwal, Rathi and Hariana was studied by polymerase chain reaction restriction fragment length polymorphism technique using the enzymes RsaI, Bst Y1 and Hae III. Both Sahiwal and Rathi are good Indian dairy breeds and survive under tough tropical conditions, while Hariana is a prominent dual-purpose breed reared both as a dairy animal and for bullock production. A total of 30 different BoLADRB3.2 alleles were observed to be present in the 3 Bos indicus breeds. Certain alleles were common amongst the three breeds while there were others that were unique to each breed. Allelic distribution amongst the three breeds showed that each breed had a unique allelic distribution pattern that was different from each other and also different from the earlier breeds studied so far for the existence of allelic variation at this locus. A dendogram was constructed based on the frequencies of the BoLA-DRB3 alleles using the UPGMA method. The Rathi and Hariana animals were genetically the most apart. The Hariana animals clustered on a different branch from the other two breeds viz. the Rathi and the Sahiwal. The smallest genetic distances for the DRB3 alleles were those between Sahiwal and Rathi (0.5461) while genetic distance between Hariana and Sahiwal was 0.6123. A comparison of the allelic frequencies of the BoLADRB3.2 locus in these 3 breeds viz. Sahiwal, Hariana and Rathi with the allelic frequencies present in the previously characterized Bos indicus Kankrej breed, which is a dual purpose breed reared both as a draught and a dairy animal, showed that the Bos indicus Sahiwal and Rathi breeds clustered into one group while the Hariana and Kankrej breeds formed another group. The Rathi and Sahiwal showed the least genetic distance of 0.5461 amongst the breeds whereas the Rathi and Kankrej, with a Nei''s genetic distance of 1.1622, were genetically the most distant apart.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.5
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• pp.379-383
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• 2002

Allelic diversity of 44 microsatellite marker loci originated from the coding regions of specific genes or the non-coding regions of barley genome was analyzed for 19 barley genotypes. Multi-allelic variation was observed at the most of marker loci except for HVM13, HVM15, HVM22, and HVM64. The number of different alleles ranged from 2 to 12 with a mean of 4.0 alleles per micro-satellite. Twenty-one alleles derived from 10 marker loci are specific for certain genotypes. The level of polymorphism (Polymorphic Information Content, PIC) based on the band pattern frequencies among genotypes was relatively high at the several loci such as HVM3, HVM5, HVM14, HVM36, HVM62 and HVM67. In the cluster analysis using genetic similarity matrix calculated from microsatellite-derived DNA profiles, two major groups were classified and the spike-row type was a major factor for clustering. Correlation between genetic similarity matrices based on microsatellite markers and pedigree data was highly significant ($r=0.57^{**}$), but these two parameters were moderately associated each other. On the other hand, RAPD-based genetic similarity matrix was more highly associated with microsatellite-based genetic similarity ($r=0.63^{**}$) than coefficient of parentage.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1685-1690
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• 2006

Kenkatha cattle, a draft purpose breed, which can survive in a harsh environment on low quality forage, was explored genetically exploiting FAO-suggested microsatellite markers. The microsatellite genotypes were derived by means of the polymerase chain reaction (PCR) followed by electrophoretic separation in agarose gels. The PCR amplicons were visualized by silver staining. The allelic as well as genotypic frequencies, heterozygosities and gene diversity were estimated using standard techniques. A total of 125 alleles was distinguished by the 21 microsatellite markers investigated. All the microsatellites were highly polymorphic with mean allelic number of 5.95${\pm}$1.9 (ranging from 3-10 per locus). The observed heterozygosity in the population ranged between 0.250 and 0.826 with a mean of 0.540${\pm}$0.171, signifying considerable genetic variation. Bottleneck was examined assuming all three mutation models which showed that the population has not experienced bottleneck in recent past. The population displayed a heterozygote deficit of 21.4%. The study suggests that the breed needs to be conserved by providing purebred animals in the breeding tract.

• Parasites, Hosts and Diseases
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• v.53 no.2
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• pp.177-187
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• 2015

Merozoite surface proteins (MSPs) of malaria parasites play critical roles during the erythrocyte invasion and so are potential candidates for malaria vaccine development. However, because MSPs are often under strong immune selection, they can exhibit extensive genetic diversity. The gene encoding the merozoite surface protein-3 (MSP-3) of Plasmodium falciparum displays 2 allelic types, K1 and 3D7. In Thailand, the allelic frequency of the P. falciparum msp-3 gene was evaluated in a single P. falciparum population in Tak at the Thailand and Myanmar border. However, no study has yet looked at the extent of genetic diversity of the msp-3 gene in P. falciparum populations in other localities. Here, we genotyped the msp-3 alleles of 63 P. falciparum samples collected from 5 geographical populations along the borders of Thailand with 3 neighboring countries (Myanmar, Laos, and Cambodia). Our study indicated that the K1 and 3D7 alleles co-existed, but at different proportions in different Thai P. falciparum populations. K1 was more prevalent in populations at the Thailand-Myanmar and Thailand-Cambodia borders, whilst 3D7 was more prevalent at the Thailand-Laos border. Global analysis of the msp-3 allele frequencies revealed that proportions of K1 and 3D7 alleles of msp-3 also varied in different continents, suggesting the divergence of malaria parasite populations. In conclusion, the variation in the msp-3 allelic patterns of P. falciparum in Thailand provides fundamental knowledge for inferring the P. falciparum population structure and for the best design of msp-3 based malaria vaccines.

• The Korean Journal of Malacology
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• v.16 no.1_2
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• pp.11-16
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• 2000

The electrophoretic banding patterns of 6-phosphogluconate dehydrogenase (PGD) in the two different chromosomal ploidy groups of Gyraulus were compared. The monomeric or dimeric banding patterns or allelic variations in a locus of PGD were observed in four diploid populations (Osan, Sohre, Kimpo and Kangwha) of G. convexiusculus occurring in Korea, whereas the isozyme banding patterns encoded by at least 3 different loci were shown in the tetraploid populations of G. (Torquis) groups collected from Michigan, the U.S.A. Of 3 different tetraploid groups, G. (T.) circumstriatus group showed 3 monomorphic isozyme banding patterns, and the other 2 populations showed some allelic variations. Such results provided good evidence to differentiate tetraploid subgenus Torquis group from the diploid Gyraulus populations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.1-21
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• 2020

Association mapping is widely used in rice and other crops to identify genes underlying important agronomic traits. Most association mapping studies use diversity panels comprising accessions with various geographical origins to exploit their wide genetic variation. While locally adapted breeding lines are rarely used in association mapping owing to limited genetic diversity, genes/alleles identified from elite germplasm are practically valuable as they can be directly utilized in breeding programs. In this study, we analyzed genetic diversity of 179 rice varieties (161 japonica and 18 Tongil-type) released in Korea from 1970 to 2006 using 192 microsatellite markers evenly distributed across the genome. The 161 japonica rice varieties were genetically very close to each other with limited diversity as they were developed mainly through elite-by-elite crosses to meet the specific local demands for high quality japonica rice in Korea. Despite the narrow genetic background, abundant phenotypic variation was observed in heading time, culm length, and amylose and protein content in the 161 japonica rice varieties. Using these varieties in association mapping, we identified six, seven, ten, and four loci significantly associated with heading time, culm length, and amylose and protein content, respectively. The sums of allelic effects of these loci showed highly significant positive correlation with the observed phenotypic values for each trait, indicating that the allelic variation at these loci can be useful when designing cross combinations and predicting progeny performance in local breeding programs.

• Journal of Plant Biotechnology
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• v.47 no.4
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• pp.298-308
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• 2020

Genetic diversity among Thaumatococcus daniellii populations in the southwestern region of Nigeria were assessed using morphometric and molecular markers to determine the population structure and existing genetic relationship for its improvement, conservation and sustainable utilisation. Populations from five locations in each of the six states were used for the study. Morphometric data were collected on folia characters and analysed for variability. Genome DNA was isolated from the plant leaf and amplified by polymerase chain reaction with inter-simple sequence repeat markers (ISSR) to determine the allelic polymorphism, marker effectiveness and genetic relationship of the population. The results showed significant variations in petiole length and leaf dimensions of the populations within and across the states. These morphometric traits are the major parameters that delimit the populations and they correlated significantly at P≤0.05. Analysis of the electrophoregram showed that the ISSR markers are effective for the diversity study. A total of 136 loci were amplified with an average of 7.16 loci per marker, 63.2% of the loci were polymorphic. The Principal Coordinate Analysis revealed that seven factors accounted for 81.6% of the variation and the dendrogram separated the populations into two major groups at a genetic distance of 10 (about 90% similarity) with sub-groups and clusters. Most populations within the state had a high degree of similarity, nonetheless, strong genetic relationship exists among populations from different states. The close relationship between populations across the states suggests a common progenitor, which are likely separated by ecological or geographical isolation mechanisms.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.465-470
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• 2002

This study presents results of electro-phoretically detectable isozyme variation in Crossing Block (CB) lines of two-rowed barley maintained by the National Crop Experiment Station. The specific objectives were to determine allelic frequencies at the four Est loci(Est1, Est2, Est4, and Est5) and their distribution over 380CB lines of two-rowed barley. A total of 17 alleles were detected over the four Est loci in these lines. There were 4 alleles (Pr, Al, Ca, and Af at the Est1 locus and their frequencies were 69.7, 1.1, 28.4, and 0.8%, respectively. At the Est2 locus, 5 different alleles (Dr, Fr, Sp, Un and a recessive null allele) were detected and their frequencies were 2.9,84.5,0.5,2.1, and 10%, respectively. four alleles (Nz, Su, At, and null were detected at the Est4 locus and the allelic frequency of Su was about 84%. Four alleles(Mi, Pi, Te, and a null allele(od)) were detected at the Est5 locus and their frequencies were 34.2, 61.0, 2.4, and 2.4%, respectively. Based on the allelic frequencies over the four Est loci, 380 CB lines were classified into 25 genotypes. The most frequent genotypes were G1(Pr-Fr-Su-Mi) and G2(Pr-Fr-Su-Pi), and their frequencies were 28.1 and 39.5%, respectively. The frequencies of other genotypes were less than 10%.