Shortest Genetic Distance Research Articles

Evaluation of germplasm resources of Sarcomyxa edulis in the Changbai Mountains of Northeast China

ABSTRACT In this study, we evaluated 16 strains of Sarcomyxa edulis from the Changbai Mountains, China through antagonism tests and ISSR molecular marker technique for cytological and molecular biological evaluation. Q-type and R-type cluster analyses were utilised to evaluate and classify agronomic traits according to the test guidelines for distinctness, uniformity, and stability. The tested strains showed antagonistic reactions. The differences in antagonistic reactions among different germplasm resources are helpful for evaluating genetic diversity and provide a basis for better development and utilisation of fungal germplasm resources. A total of 330 bands were amplified by 21 ISSR primers, including 321 polymorphic bands. The percentage of polymorphic bands observed was 97.07%. Using PopGen32 software, the effective number of alleles (Ne), Nei's gene diversity index (H), and Shannon's diversity index (I) were calculated, yielding average values of 1.6638, 0.3796, and 0.5480, respectively. In addition, the genetic similarity coefficient of 16 strains ranged from 0.4306–0.7778. According to the Q-type clustering, the tested strains were classified into two categories based on the Euclidean distance of 8.52. While R-type cluster analysis revealed a significant correlation between the traits. At the Euclidean distance of 6.298, the traits could be classified into three distinct categories. According to the findings, all 16 strains demonstrated high genetic diversity. The ISSR clustering results revealed that strains with shorter genetic distances were more similar in specific traits. However, there were notable differences between the results of comprehensive trait clustering (Q-type clustering) and ISSR clustering.

Highly clonal Pythium aphanidermatum population infecting greenhouse plants in Japan

A highly controlled environment inside the greenhouse could provide suitable temperatures, nutrients, and light intensity for the crops. However, Pythium root rot continually threatens the productivity of numerous kinds of crops in hydroponic systems, including tomato, poinsettia, spinach, lettuce, and rose. It is caused by Pythium aphanidermatum, which grows well in the warmer temperatures inside the green house and is able to survive in low temperatures as well. In this research, we studied 165 isolates of P. aphanidermatum collected from three prefectures in Japan. We developed 10 reliable microsatellite markers to evaluate the genetic diversity of P. aphanidermatum. In total, 34 multilocus genotypes (MLGs) were observed. The index of association suggested that the population was highly clonal. This result was supported by the low result of Fst (0.075) and the short genetic distance per locus visualized in the minimum spanning network. The clonal population suggested that asexual reproduction was dominant.

Genetic diversity and population structure of indigenous guinea fowl (Numida meleagris) in Benin using simple sequence repeat markers.

This study aimed to assess the genetic diversity and population structure of 12 guinea fowl phenotypes from three climatic zones (Guinean, Sudano-Guinean and Sudanian) of Benin. A total of 96 adult guinea fowl, aged at least 6months, were selected for blood sampling. Fragment analysis was carried out using 17 polymorphic microsatellite markers. The informative marker combinations revealed a total of 83alleles across all loci, with an average of 5alleles per locus and a mean polymorphic information content (PIC) of0.793. This study showed an observed heterozygosity of0.492. The inbreeding coefficient values ranged from0.086 in white phenotype to0.226 in cinnamon, showing a deficit of heterozygotes, suggesting a moderate inbreeding level. A relatively low population differentiation was observed, with a mean fixation index(Fst) value of0.033. The short genetic distances between phenotypes, unlike the strong genetic identities, revealed high genetic proximity between the 12 phenotypes of indigenous guinea fowl in Benin. These data indicate the existence of a single indigenous guinea fowl population with high intra-population genetic diversity with respect to climatic zones or phenotypes. This study will help in the selection of parental breeding stock for genetic improvement programs, as well as in the conservation for biodiversity maintenance and sustainable use of the indigenous guinea fowl in the study zones in Benin.

Cosmopolitan abyssal lineages? A systematic study of East Pacific deep-sea squat lobsters (Decapoda: Galatheoidea: Munidopsidae)

Munidopsid squat lobsters are among the most abundant decapods at abyssal depths and the most diverse squat lobster group in the East Pacific region. During recent cruises along the East Pacific, many deep-sea squat lobsters were collected. Among these, we described five new munidopsid species supported both by morphological characters and molecular phylogenetics: Munidopsis girguisi sp. nov., M. nautilus sp. nov., M. testuda sp. nov., M. cortesi sp. nov. and M. hendrickxi sp. nov. We also report new records of several Munidopsis species across the East Pacific that increase the species distribution ranges. Here, we reconstructed the phylogenetic relationships of the East Pacific species in relation to other Galatheoidea using one nuclear and two mitochondrial gene fragment(s); we also performed single locus species delimitation analyses to explore the species status of various East Pacific munidopsid taxa. The new taxa were photographed, illustrated and imaged with micro-computed tomography. The phylogenetic results show that: (1) Janetogalathea californiensis, previously included in the family Galatheidae, nests within Munidopsidae; (2) the phylogenetic position of Phylladiorhynchus and Coralliogalathea as belonging in Galatheidae is not supported; and (3) Munidopsis is paraphyletic, agreeing with recent systematic hypotheses. Short genetic distances and species delimitation analyses suggested that a clade mostly constituted by abyssal species might include fewer species than currently considered, as species show a wider geographic range than previously considered, conforming with traditional hypotheses of cosmopolitanisms in abyssal species. ZooBank: urn:lsid:zoobank.org:pub:CED9EB18-7061-47A7-B2FF-7F1DAFCC7B12.

Molecular Phylogeny of Selected Kenyan Eucalyptus Species Inferred from MatK, rbcL and TrnL-F Genes and Their Suitability for Power Transmission Poles

Genus Eucalyptus belongs to the family Myrtaceae and consists of more than 900 species, various hybrids and varieties. The major species that are grown in Kenya are Eucalyptus grandis, E. globulus, E. saligna and E. camaldulensis. Most Eucalyptus species are highly dependent on rainfall and this is challenged by climatic changes owing to global warming making it difficult to effectively match the availability of mature trees and the market demand especially for use as power transmission poles. With the widespread availability of other naturally occurring Eucalyptus species such as E. camaldulensis and E. globulus, it becomes important to determine the genetic diversity and to analyze the phenotypic traits of these species for suitability as power transmission poles in order to counter the overdependence on E. grandis. Phenotypic traits investigated included measuring total tree height and diameter at breast height (DBH), while molecular data were obtained from sequencing MatK, rbcL and TrnL-F genes from selected species and evolutionary analyses such as nucleotide substitution rates, base composition disparity indices, evolutionary divergence, nucleotide diversity indices and phylogeny construction were conducted in MEGA 11. Significant differences in DBH and height among Eucalyptus species were observed when the phenotypic data were subjected to ANOVA. In this study, E. robusta, E. paniculata, E. maculata, E. dunnii, E. camaldulensis and E. citriodora are fit to be used as power transmission poles but they are limited by their short height. However, E. tereticornis and E. glaucina have the desired DBH and height and hence can be used as substitutes for E.grandis. Generally, the molecular phylogeny study has shown that the studied Eucalyptus species are closely related and form various monophyletic clades which can be attributed to the short genetic distances, low substitution rates, low nucleotide bias disparity indices and low diversity scores. Further phylogenetic and gene expression studies involving more Eucalyptus species are needed to better understand Eucalyptus phylogeny, and diversity and identify species with similar genetic make-up to that of E. grandis which has been used extensively for the provision of electricity transmission poles.

PCR Analysis for Genetic Distances of Two Charybdis Crab Populations.

Genomic DNA (gDNA) set apart from two populations of Korean Charybdis crab (Charybdis japonica) was augmented by PCR experiments. The five oligonucleotides primers (ONT-primers) were spent to yield the number of unique loci shared to each crab population (ULSECP) and number of loci shared by the two crab populations (LSTCP). 305 fragments (FRAGs) were identified in the Charybdis crab population A (CCPA), and 344 in the Charybdis crab population B (CCPB): 44 number of ULSECP (14.43%) in the CCPA and 110 (31.98%) in the CCPB. 44 number of LSTCP, with an average of 8.8 per primer, were detected in the two crab populations. The bandsharing (BS) value between entity's no. 01 and no. 10 was the lowest (0.371) between the two CCPs. The average bandsharing (ABS) values of individuals in the CCPA (0.575±0.014) were lesser than in those originated from the CCPB (0.705±0.011) (p < 0.05). The polar hierarchical dendrogram (PHD) achieved by the five ONT-primers denotes three genetic clusters (GCs): cluster I (CHARYBCRAB 01, 04, 05, 06, and 08), cluster II (CHARYBCRAB 02, 03, 07, 09, 10, and 11) and cluster III (CHARYBCRAB 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, and 22). The shortest genetic distance (GD) displaying significant molecular difference (MD) was between individuals CHARYBCRAB no. 18 and CHARYBCRAB no. 17 (0.055).

The complete chloroplast genome sequence of Veratrum nigrum L.

The complete chloroplast genome of an important medicinal plant, Veratrum nigrum Linnaeus, was sequenced. The entire circular genome is 151,580 bp in length, with 37.7% GC contents. The genome has a large single-copy (LSC) region with a length of 81,806 bp, a small single-copy (SSC) region with a length of 17,472 bp, and two inverted repeat regions (IRs) with a length of 26,151 bp. It harbored 131 genes, including 85 protein coding genes, 38 tRNA genes, and eight rRNA genes. Phylogenetic analysis suggested V. nigrum formed a monophyletic clade with relatively short genetic distance to Veratrum oxysepalum and Veratrum taliense. This study will provide theoretical basis for further study on plant genetics phylogenetic research.

Integrative QTL Identification, Fine Mapping and Candidate Gene Analysis of a Major Locus qLTG3a for Seed Low-Temperature Germinability in Rice

Low-temperature germinability (LTG) is an important agronomic trait that can affect the planting time, planting area, and grain yield of staple crops, such as rice. However, the genetic mechanism of LTG is still unclear. In this study, a multi-parental permanent population with 208 single segment substitution lines (SSSLs) was used to conduct a genetic dissection for LTG across four cropping seasons. LTG was a typical quantitative trait with a high combined broad-sense heritability of 0.71. By comparison with the recipient parent, Huajingxian74, 24 SSSLs were identified as carrying LTG QTLs, which were further merged into integrated QTLs with shorter genetic distances by substitution mapping. Finally, 14 LTG QTLs were mapped on ten chromosomes, including seven positive-effect and seven negative-effect QTLs, with additive effect contributions ranging from 19.2 to 39.9%. qLTG3a, a main-effect and novel QTL, was confirmed by bulk segregant analysis using an F2 segregating population, and five key recombinants were selected to develop F3 populations for progeny testing. Marker-trait association analysis fine mapped qLTG3a to a 332.7-kb physical region between markers M6026 and M6341. Within this interval, 40 annotated genes were revealed, and three genes (Os03g0213300, Os03g0214400, and Os03g0214600) were considered as pivotal candidate genes for qLTG3a based on their sequence variations and expression patterns. Besides low temperature, qLTG3a can also enhance seed germination under standard temperature and osmotic stress. In summary, this study identified some genetic factors regulating LTG and opened a new window for breeding elite direct-seeded rice varieties. It will help reduce the climate risk in the production process of rice, which is of great significance to ensuring food security.

Genetic diversity and species identity of the critically endangered Rote Island snake-necked turtle, Chelodina mccordi Rhodin, 1994

The endemic Chelodina mccordi is considered extinct in the wild; however, ex-situ populations are thriving and sampled for our genetic diversity assessment. We used three sequences resulting from blood and tissue samples of five individual turtles amplified for 650-bp cytochrome oxidase I (COI) fragment of the mitochondrial DNA. We analysed a total of 30 barcoding DNA sequences for phylogenetic relationships and genetic distances among Chelodina spp. Nucleotide diversity of eight C. mccordi samples is 0.007 ± 0.001 with a haplotype diversity of 0.893 ± 0.086. All these samples form a monophyletic clade that is sister to a clade of Australian and New Guinean long-necked turtles. Genetic distances calculated using Kimura 2-paramater model among C. mccordi sequences range between 0.2% and 1.5%, while a few others are without distance. The shortest genetic distance is between individuals from Rote Island, whereas the longest distance was found between individuals, each of which was derived from parental stocks originating in Rote and Timor islands. A genetic distance of 1.1% - 1.5% is likely to denote distinction at subspecies level. Results of this study could help in reintroducing captive individuals into their natural habitats. Thus, captive breeding programme of this species may help its conservation.

Deep-Sea Carbonates Are a Reservoir of Fossil Microbes Previously Inhabiting Cold Seeps

Carbonates are globally distributed particularly around deep-sea cold seeps. The embedded microbes are fossil records of the past bioprocess but metagenomes of the carbonates have not been fully studied. In this study, we report microbial community structures and genomes of dominant species in cold-seep carbonates from the South China Sea (SCS) and Gulf of Mexico (GoM). The carbonates contained both anaerobic microbes represented by methane oxidizing archaea (ANME) and aerobic ammonia-oxidizing archaea (AOA). The samples from GoM were mostly composed of small microbial groups, indicating heavy degradation of the fossil microbes. The composition of the carbonate communities differed from that of cold seep sediments, suggesting alteration of cold-seep microbial structures during formation and weathering of carbonates. Extraction of 18S rRNA genes from metagenomic reads revealed prevalence of fungal species in the carbonates of the GoM. Genome binning resulted in 10 genomes for dominant prokaryotic species. The ANME genomes showed a short genetic distance to the relatives from the current cold seep sediments; the AOA genomes were affiliated with alpha ecotype dominating deep-sea sediments. Our study reports the genomes in ancient carbonates and sheds lights on microbial role in formation and bioweathering of carbonates.

Phylogenetic Clustering among Asylum Seekers with New HIV-1 Diagnoses in Montreal, QC, Canada.

Migrants are at an increased risk of HIV acquisition. We aimed to use phylogenetics to characterize transmission clusters among newly-diagnosed asylum seekers and to understand the role of networks in local HIV transmission. Retrospective chart reviews of asylum seekers linked to HIV care between 1 June 2017 and 31 December 2018 at the McGill University Health Centre and the Jewish General Hospital in Montreal were performed. HIV-1 partial pol sequences were analyzed among study participants and individuals in the provincial genotyping database. Trees were reconstructed using MEGA10 neighbor-joining analysis. Clustering of linked viral sequences was based on a strong bootstrap support (>97%) and a short genetic distance (<0.01). Overall, 10,645 provincial sequences and 105 asylum seekers were included. A total of 13/105 participant sequences (12%; n = 7 males) formed part of eight clusters. Four clusters (two to three people) included only study participants (n = 9) and four clusters (two to three people) included four study participants clustered with six individuals from the provincial genotyping database. Six (75%) clusters were HIV subtype B. We identified the presence of HIV-1 phylogenetic clusters among asylum seekers and at a population-level. Our findings highlight the complementary role of cohort data and population-level genotypic surveillance to better characterize transmission clusters in Quebec.

Pathological, molecular and phylogenic study of fowlpox virus in domesticated chickens of Tikrit City, Iraq

Fowlpox virus (FPV) is one of the viruses affecting chickens worldwide, causing pathological and economic losses in the poultry industry. Viral lesions are easily recognizable by the eye and usually appear in the featherless areas, especially the head. Moreover, the virus could lead to blindness and mortality in some cases. This study diagnosed the suspected fowlpox cases, identified and classified the causative agent. We also analyzed the differences and similarities of closely related viruses at the neighboring and regional countries. Fifty samples were collected from three locations of Tikrit city from the domesticated chickens, which showed cutaneous lesions. Virus DNA was extracted directly from tissue samples before the nested PCR technique was performed. The virion core protein (P4b) gene is partially sequenced and analyzed with routine histological sectioning. Results showed that the virus causes pock lesions of dermal hyperplasia and hyperkeratosis. Hyperplasia and congestion of the chorioallantoic membrane were also recorded. The study also showed that the DNA of FPV could be extracted directly from animal tissue without further purification. The sequence analysis showed that the FPV was confirmed in all samples clustered in clade A identical with Iranian and Egyptian isolates. In conclusion, this study approved that the virus belongs to the classical dermal type of poxviruses and the short genetic distances between viruses related to closely neighboring countries. We also concluded that the conservative P4b gene included mutation sites that make this gene practical for diagnosing the virus and phylogenetic analysis.

Diversity of biometric and morphological traits among sheep breeds in Nigeria

Towards assessment of variations within and between sheep; biometric and morphological data of the four breeds of sheep found in Nigeria were collected using multi-stage samplin method. A total of 46 Balami, 30 Uda, 36 Yankasa and 37 WAD were sampled. Stepwise multiple regression procedure was used to find the best linear combination of metric variables that best predict the body weight. Principal component analysis of biometric and morphological traits was carried out. Simple discriminant analysis procedure was used to classify the breeds. Cluster analysis was done using the model building specificationinterface. Head length (HL), chest girth (CG), leg length (LL), and tail length were the only linear body measurements that were significant (P&lt;0.01) in predicting body weight of sheep in the overall prediction equation. Body weight and all the linear body measurements had their highest loadings on principal component 1 (PC1). Tassel was the only variable that had its highest loading on PC2. Tail type and state (location) were the variables that bestdescribes the third component (PC3). Sex and hair type were variables that best described the forth component (PC4). Discriminant analysis showed that 70.59% of sheep sampled as Balami were classified as pure breed. Sheep sampled as WAD and Yankasa had 100% conformation while Balami and Uda had 70.59% and 60%, respectively in conformation to the classifying features of their breed based on discriminant analysis. The farthest genetic distance (5.48) was observed between Balami and WAD while the shortest genetic distance (1.26) was observed between Balami and Uda. Improvement of growth traits of sheep breedsin Nigeria is recommended through the use of either Balami or Uda as sire and either WAD or Yankasa as dam.

Reproductive and genetic roles of the maternal progenitor in the origin of common wheat (Triticum aestivum L.).

Common wheat (Triticum aestivum L., AABBDD genome) is thought to have emerged through natural hybridization between Triticum turgidum L. (AABB genome) and Aegilops tauschii Coss. (DD genome). Hybridization barriers and doubling of the trihaploid F1 hybrids’ genome (ABD) via unreduced gamete fusion had key roles in the process. However, how T. turgidum, the maternal progenitor, was involved in these mechanisms remains unknown. An artificial cross‐experiment using 46 cultivated and 31 wild T. turgidum accessions and a single Ae. tauschii tester with a very short genetic distance to the common wheat D genome was conducted. Cytological and quantitative trait locus analyses of F1 hybrid genome doubling were performed. The crossability and ability to cause hybrid inviability did not greatly differ between the cultivars and wild accessions. The ability to cause hybrid genome doubling was higher in the cultivars. Three novel T. turgidum loci for hybrid genome doubling, which influenced unreduced gamete production in F1 hybrids, were identified. Cultivated T. turgidum might have increased the probability of the emergence of common wheat through its enhanced ability to cause genome doubling in F1 hybrids with Ae. tauschii. The ability enhancement might have involved alterations at a relatively small number of loci.

Genotypic and phylogenetic diversity of new isolates of terrestrial Xanthophyceae (Stramenopiles) from maritime sandy habitats

ABSTRACT Xanthophyceae (Stramenopiles) are common microalgae in soil habitats, but not commonly known from maritime sandy habitats. Here we studied the genetic diversity of nine new isolates of Xanthophyceae from coastal habitats using two chloroplast-encoded markers. The isolates exhibited only three morphotypes. The sequence comparisons uncovered a respectable phylogenetic diversity, including novel infraspecific genotypes, among the isolates. The phylogenetic analyses of full rbcL gene sequences identified eight of the isolates to five named species based on monophyletic origins and short genetic distances with defined taxonomic reference strains. One strain, representing a coccoid species, was within a so far unrecognised lineage of Xanthophyceae. In four clades of the rbcL phylogeny, the coastal isolates were most closely related to strains from Antarctic soil habitats. Comparisons of the psbA/rbcL spacer region sequences, a highly variable molecular marker, uncovered a fine-scale structuring within a species which was consistent with habitat preferences. The new maritime isolates exhibited genotypes distinct from those of the same species from other habitats. It suggests that the environment selects for specific genotypes in these pioneering algae.

Morphological and Genetic Relation in Hybrids of Triatomines (Hemiptera: Reduviidae) of the Phyllosoma Complex from Mexico

AbstractTriatoma longipennis Usinger 1939, Triatoma pallidipennis (Stal, 1872), and Triatoma picturata Usinger 1939 are considered among the species with the highest transmission capacity of Chagas disease in Mexico, with an impact on health mainly in rural zones and places with worn-out dwellings. There have been previous studies on the phylogenetic relationship of these species of the Phyllosoma complex using molecular approaches, in addition to analyzing morphological characters. However, one of the problems in the field is the presence of hybrids that due to the short genetic distance between species, and such organisms have not yet been identified and could be confused with parental organisms. In this work, we analyzed genotypical and phenotypic characters, between the species and the three possible hybrids resulting from the cross between the species. In the analysis of wings morphology, we found that the dominant phenotype in hybrids was that of T. pallidipennis, having a higher dominance than T. longipennis. Besides, the use of the COI marker amplified in DNA of parentals and the three possible hybrids showed by neighbor-joining phylograms a greater association of the hybrids with T. longipennis, in agreement with the analysis of genetic distances and polymorphic sites. Thus, the morphological data demonstrate the high dominance of T. pallidipennis and the molecular data of T. longipennis in its hybrids, in such a way that it is possible to differentiate hybrids from parental species.

The genetic diversity and heterotic groups of 169 Chinese semi-winter rapeseed (Brassica napus) cultivars and inbred lines

Until now, no distinct heterotic groups have been established in many rapeseed-growing countries. Numerous modern breeding lines with desirable seed quality have been developed but the loss of genetic diversity would be problematic. Simple sequence repeat markers covering all 19 B. napus linkage groups were used to evaluate the genetic diversity and to classify the heterotic groups of 169 Chinese semi-winter cultivars or inbred lines. The results indicate moderate genetic differentiation among the 169 accessions, which distributed in 10 major groups according to their pedigrees or origins. The Chinese accessions could be divided into two genotypes: northern restorers and southern maintainers for Polima cytoplasm male sterility. The maintainers consisted of nine clades originating from 10 major rapeseed-growing provinces in the upper, middle and lower reaches of the Yangtze River. The mid-parent heterosis on plant height and yield ability of the intragroup crosses was inferior to that of the intergroup hybrids. When the intragroup parental combinations with short genetic distances (GD) were included in all regressing data, GD is significantly correlated to heterosis level. Three major heterotic patterns were identified: (1) northern restorer × southern maintainer, (2) maintainer from the upper reaches of the Yangtze River × maintainer from the lower reaches of the Yangtze River and (3) maintainer from the middle Yangtze River × maintainer from the lower reaches of the Yangtze River. For the first time, the results showed the outline of heterotic groups in Chinese rapeseed under the conditions of the Huang-Huai River region.

Genetic Distances between Two Echiuran Populations Discriminated by PCR.

ABSTRACTGenomic DNA extracted from representatives of two populations, Gunsan and Chinese, of Urechis spp. was amplified using PCR with several primers. The band-sharing (BS) value between individuals no. 05 from the Gunsan population and no. 22 from the Chinese population was 0.206, which was the lowest recognized value. Oligonucleotides primer OPC-04 revealed 44 unique loci, which distinguished the Chinese population. Primer OPB-17 allowed the discovery of 22 loci shared by the two populations, which were present in all samples. Based on the average BS results, individuals from the Gunsan population demonstrated lower BS values (0.661±0.012) than did those from the Chinese population (0.788±0.014; p<0.05). The shortest genetic distance (GD) displaying a noteworthy molecular difference was between individuals CHINESE no. 12 and no. 13 (GD=0.027). Individual no. 06 from the Gunsan population was most distantly related to CHINESE no. 22 (GD=0.703). A group tree of the two populations was constructed by UPGMA Euclidean GD analysis based on a total of 543 fragments generated using six primers. The explicit markers recognized in this study will be used for genetic analysis, as well as to evaluate the species security and proliferation of echiuran individuals in intertidal regions of the Korean Peninsula.

Genetic diversity and relationships among three Southern African Nguni cattle populations

The Nguni cattle breed has distinct populations that are adapted to the different ecological zones of Southern Africa. This study was carried out to assess genetic diversity and establish the relationships among South African (SA), Mozambican (Landim), and Swazi Nguni cattle populations, using 25 microsatellite markers. Genotypic data were generated from deoxyribonucleic acid (DNA) samples of 90 unrelated individuals of the three cattle populations, collected from government conservations and stud herds. DNA profiles of five local beef breeds were used as the reference populations. Most of the 25 microsatellite markers were highly polymorphic across the studied populations, with an overall polymorphic information content (PIC) mean of 0.676. Genetic diversity within populations was high with expected heterozygosity varying from 0.705 ± 0.024 (Landim) to 0.748 ± 0.021 (SA Nguni) and mean number of alleles being highest in the SA Nguni (7.52 ± 0.42). Average observed heterozygosity (0.597 ± 0.046) compared to the expected heterozygosity (0.719 ± 0.022) was lowest for the Swazi Nguni, which also had a high number of Hardy-Weinberg Equilibrium (HWE) deviated loci (13), confirming the relatively high level of inbreeding (0.158 ± 0.058) in that population. Analysis of molecular variance revealed only 9.61% of the total variation between the populations and 90.39% within populations. A short genetic distance (0.299) was observed between Landim and Swazi Nguni, with the SA Nguni (> 0.500) being the most genetically distant population. The distant relationship between SA Nguni and the other two Nguni cattle populations was further confirmed by a principal coordinates analysis. The three Nguni populations clustered independently from each other, despite some evidence of admixture. Therefore, it can be concluded that SA Nguni, Landim, and Swazi Nguni populations in Southern Africa exhibit high levels of genetic diversity and are genetically distant; with the two latter populations being less genetically apart. These results present useful information for the development of strategies for regional management of animal genetic resources, through conservation and sustainable utilisation.

Genetic Distances between Two Cultured Penaeid Shrimp (Penaeus chinensis) Populations Determined by PCR Analysis.

Genomic DNA samples were obtained from cultured penaeid shrimp (Penaeus chinensis) individuals such as fresh shrimp population (FSP) and deceased shrimp population (DSP) from Shinan regions in the Korean peninsula. In this study, 233 loci were identified in the FSP shrimp population and 162 in the DSP shrimp population: 33 specific loci (14.2%) in the FSP shrimp population and 42 (25.9%) in the DSP population. A total of 66 (an average of 9.4 per primer) were observed in DSP shrimp population, whereas 55 unique loci to each population (an average of 7.9 per primer) in the FSP shrimp population. The Hierarchical dendrogram extended by the seven oligonucleotides primers indicates three genetic clusters: cluster 1 (FRESH 01, 02, and DECEASED 12, 13, 15, 16, 17, 19, 20, 22) and cluster 2 (FRESH 03, 04, 05, 06, 07, 08, 09, 10, 11, and DECEASED 14, 18, 21). Among the twenty-two shrimp, the shortest genetic distance that exposed significant molecular differences was between individuals 20 and 16 from the DSP shrimp population (genetic distance=0.071), while the longest genetic distance among the twenty-two individuals that established significant molecular differences was between individuals FRESH no. 02 and FRESH no. 04 (genetic distance=0.477). In due course, PCR analysis has revealed the significant genetic distance among two penaeid shrimp populations.