Microsatellite Analysis Characterizes Burkina Faso as a Genetic Contact Zone Between Sahelian and Djallonké Sheep

A total of 123 sheep belonging to the Djallonké, Mossi, and Burkina-Sahel breeds, along with 41 Spanish Xalda sheep were genotyped for 27 microsatellites. The pair Djallonké-Mossi had the highest between breeds molecular coancestry. Admixture analysis informed on the parental role of the Burkina-Sahel and Djallonké breeds. The Mossi breed was a hybrid population nearer to the Djallonké breed. Only half of the Mossi individuals were correctly assigned to their breed. The Burkina-Sahel and Djallonké breeds can be considered ancestrally different genetic entities. Differentiation between the Djallonké and Mossi breeds may be due to introgression of Sahelian sheep.     

Mitochondrial DNA diversity and origins of domestic goats in Southwest China (excluding Tibet)

Southwest China contains about one third Chinese indigenous goat breeds representing special economic and ecological characteristics. Mitochondrial DNA (mtDNA) D-loop sequences of 312 individuals (including 109 new individuals, 203 individuals retrieved from GenBank) from 18 Chinese domestic goat breeds were used to investigate breed genetic diversity, origin and phylogeography. All goat breeds in this study proved to be extremely diverse, average haplotype diversity and nucleotide diversity being 0.9829 ± 0.0027 and 0.03615 ± 0.03257, respectively. The 312 sequences gave 148 different haplotypes. Phylogenetic analyses revealed that there were two mtDNA haplogroups identified in domestic goats in Southwest China, in which haplogroup A was predominant. Mismatch analysis showed haplogroup A had experienced population expansion events, whereas haplogroup B did not. Amova analysis showed there was no significant geographical structuring. Almost 86.23% of genetic variation was included in the within-breed variance component and only 3.5% was observed among the four geographic provinces. The results of this study contribute to the knowledge of the genetic structure and origin of domestic goats in Southwest China.     

Multivariate characterization of morphological traits in Burkina Faso sheep

A total of 6440 female sheep from Burkina Faso were scored for seven body measurements and four qualitative morphological traits. Sampling included the three main environmental areas and sheep breeds of Burkina Faso: the Sahel area (Burkina-Sahel sheep), the Sudan-Sahel area (Mossi sheep) and the Sudan area (Djallonké sheep). Canonical analyses showed that differences in body measurements between the Sudan and the Sudan-Sahel sheep were small even though most body traits showed higher average values in the Burkina-Sahel sheep: the shortest Mahalanobis distance was found between the Sudan and the Sudan-Sahel populations (1.54), whilst that between the Sudan and the Sahelian populations was the largest (7.88). Discriminant analysis showed that most Sudan (Djallonké) individuals (60.85%) were classified as Sudan-Sahel (Mossi) individuals whilst most Burkina-Sahel individuals were classified into their environmental area of sampling (89.46%). Correspondence analyses indicated that the Burkina-Sahel sheep population clustered together with dropping ears, black and brown colour patterns and presence of wattles, the Sudan sheep were closely associated with long hair and vertical and curled ears and that the Sudan-Sahel sheep did not have clear associations with qualitative phenotypic traits. At the morphological level, the Sudan-Sahel (Mossi) sheep population can be considered a geographical subpopulation belonging to the Djallonké breed, showing some particularities, namely larger body size, due to the particular environmental condition of the area in which it is managed and a continuous gene flow from Sahelian sheep, The information reported in this study will be the basis for the establishment of further characterization, conservation and selection strategies for Burkina Faso sheep.     

Microsatellite characterization of Cimarron Uruguayo dogs

Various genetic markers, including microsatellites, have been used to analyze the genetic polymorphism and heterozygosity in canine breeds. In this work, we used nine microsatellite markers to investigate the genetic variability in Cimarron Uruguayo dogs, the only officially recognized native canine breed in Uruguay. DNA from 30 Cimarron Uruguayo dogs from northeastern and southern Uruguay was analyzed. The allelic frequencies for each microsatellite, the genetic variability and the consanguinity were calculated, as were the polymorphic information content (PIC) and the probability of exclusion (PE). All of the microsatellites studied were polymorphic. FH 2361, FH 2305 and PEZ 03 were the most informative, with PIC values > 0.7, in agreement with results for other canine breeds. The PE values for the markers were within the ranges previously described and were generally greater for microsatellites with higher PIC values. The heterozygosity value (0.649) was considered high since only nine microsatellites were analyzed. Compared with data for other breeds, the results obtained here indicate that Cimarron Uruguayo dogs have high genetic diversity.     

Differential effects of nitrogen and phosphorus enrichment on growth of dwarf Avicennia marina mangroves

The effects of N and P enrichment were investigated on growth and physiological responses of dwarf Avicennia marina mangroves in a hypersaline (58 ± 8 psu) field site in Richards Bay, South Africa. It was hypothesized that at high salinities mangroves allocate more resources to roots than shoots, and that nutrient enrichment with N and P will shift resource allocation to shoots and enhance growth and productivity. In unvegetated areas of the dwarf zone, 1-year-old A. marina seedlings were planted in pots and enriched bimonthly with N, P, N + P, or remained unfertilized (control-C), and growth and morphology of plants were monitored for 2 years. Enrichment with N and N + P shifted resource allocation to shoots from 38% to 55%, and increased dry biomass accumulation by over 500%, compared to the control treatment. In the N and N + P treatments, plant height, number of leaves, leaf chlorophyll content and photosynthesis increased by over 50%, 330%, 30% and 30%, respectively, compared to the C and P treatments. Enrichment with N and N + P increased N concentrations in roots by over 60% (from 1.0 ± 0.1% to 1.6 ± 0.2% of dry mass) and in shoots by over 100% (from 1.3 ± 0.1% to 2.7 ± 02% of dry mass). Plants enriched with P alone were similar to those of the control. This study has demonstrated that dwarf A. marina in Richards Bay is N limited, and that N enrichment shifts resource allocation from roots to shoots and increases growth and productivity.     

Molecular phylogeography of Ruditapes philippinarum in the Northwestern Pacific Ocean based on COI gene

To examine the pattern of phylogeography of Ruditapes philippinarum, a length of 644-bp gene fragment of the mtDNA COI was sequenced. A total of 170 individuals from 19 locations were analyzed yielding 74 haplotypes, most of which were unique. The levels of haplotype diversity and nucleotide diversity for the species ranged from 0.80 ± 0.16 (Notsuke Bay) to 1.00 ± 0.13 (Nanao Bay, Miyazu Bay, Dalian 1 and Ariake), and from 0.002 ± 0.001 (Notsuke Bay) to 0.011 ± 0.006 (Qingdao), respectively. Both the phylogenetic (NJ tree) and minimum spanning trees (MST) showed three significant genealogical clusters corresponding to sampling localities, a genetic differentiation speculated to be caused by the isolation of the marginal seas of the Northwestern Pacific during Pleistocene low sea-level stands. Both AMOVA and pairwise Fst analyses revealed significant genetic differentiation between the populations from Japan and China. The pattern of isolation by distance was also detected in this species (r = 0.50, P < 0.001). Both mismatch distribution analysis and the neutrality tests showed that R. philippinarum had undergone a recent population expansion. The estimate of population expansion time was about 425 kya-1580 kya.     

Population genetic structure and historical demography of grey mullet, Mugil cephalus, along the coast of China,inferred by analysis of the mitochondrial control region

Population genetic structure and historical demography of grey mullet, Mugil cephalus, along the coast of China were examined with a 389-bp segment of mtDNA control region. In total, 117 samples were collected from seven locations and 77 haplotypes were obtained. No haplotype was concurrently presented in all the samples, and samples in Southern and Northern regions had distinctly different haplotypes. Sorting of the data cladistically into phylogenetic trees indicated that these haplotypes can be divided into two main clades. Analysis of molecular variance (AMOVA) indicated significant genetic differentiation among subpopulations in different regions (φ_CT = 0.9505, p < 0.01). The average pairwise differences and φ_ST values (0.8943–0.9464) between regional populations were significant. The net Tumura and Nei genetic distance (0.5577 ± 0.1421) between the two groups was large. The deep and unique divergence between the two groups suggested that each group is likely to represent a distinct species. In contrast to the great genetic divergence on a broad scale, small but significant population subdivisions at a less spatial scale were also detected both in Southern and Northern regions, which support the conclusion that M. cephalus has limited dispersal potential. High haplotype diversity (h = 0.8716 ± 0.1462) and low nucleotide diversity (π = 0.0046 ± 0.0030) were found among the three Northern samples. Among the four Southern samples, however, extraordinarily high levels of both haplotype diversity (h = 0.9886 ± 0.0057) and nucleotide diversity (π = 0.0425 ± 0.0212) were detected. The different polymorphisms suggest an apparent distinguishing demographic history between regionally Southern and Northern populations, though mismatch distribution analyses and neutrality tests implied a late Pleistocene population expansion of both Northern and Southern populations.     

Analysis of genetic relationships between 10 cattle breeds with 17 microsatellites

To guide genetic conservation programmes with objective criteria, general genetic variability has to be taken into account. This study was conducted to determine the genetic variation between 10 cattle breeds by using 17 microsatellite loci and 13 biochemical markers (11 blood groups, the transferrin and β-casein loci). Microsatellite loci were amplified in 31–50 unrelated individuals from 10 cattle breeds: Charolais, Limousin, Breton Black Pied, Parthenais, Montbéliard, Vosgien, Maine-Anjou, Normande, Jersey and Holstein. Neighbor-joining trees were calculated from genetic distance estimates. The robustness of tree topology was obtained by bootstrap resampling of loci. A total of 210 alleles of the 17 microsatellites were detected in this study and average heterozygosities ranged from 0·53 in the Jersey breed to 0·66 in the Parthenais breed. In general, low bootstrap values were obtained: with the 17 microsatellites, the highest bootstrap values concerned the Holstein/Maine-Anjou grouping with an occurrence of 74%; with the biochemical markers, this node had an occurrence of 79% and the Charolais/Limousin grouping appeared with an occurrence of 74%; when microsatellites and biochemical polymorphism were analysed together, the occurrence of the Holstein/Maine-Anjou grouping was 90% and that of the Charolais/Limousin grouping was 42%. These results suggest that 30 microsatellites, a number currently considered as sufficient to distinguish closely related breeds is, in fact, probably insufficient.     

Embryo production after in vitro fertilization with frozen-thawed, sex-sorted, re-frozen-thawed bull sperm

The objective of this study was to determine the in vitro fertilizing capacity of bull sperm derived from fresh or frozen samples and subjected to sex sorting and re-cryopreservation. Four sperm types were assessed for their ability to fertilize and sustain early embryo development in vitro. Semen from three Bos taurus bulls of different breeds (Jersey, Holstein and Simmental) was collected and either sorted immediately and then frozen (SF) or frozen for later sorting. Frozen sperm destined for sorting were thawed, sex-sorted, and re-frozen (FSF) or thawed, sex-sorted (FS), and used immediately for in vitro fertilization (IVF). Frozen-thawed nonsorted semen from the same ejaculate was used as a control. Oocytes from donor cows were aspirated via ovum pick-up and matured in vitro prior to IVF and culture. On average, 19.0 ± 1.7 (mean ± SEM) oocytes were aspirated per donor cow, of which 74.4 ± 2.2% were selected for maturation. The proportion of cleaved embryos (Day 3) did not differ between sperm groups (P = 0.91). Likewise, IVF with FSF sperm resulted in similar Day 7 blastocyst rates (as a percentage of total oocytes) as those of control, SF, and FS sperm (FSF, 34.5 ± 4.7; control, 32.2 ± 4.6; SF, 35.9 ± 4.8; and FS, 26.9 ± 4.1%; P = 0.23). These encouraging results show that frozen-thawed sex-sorted sperm may be re-frozen and used for in vitro embryo production with similar blastocyst production as that of nonsorted frozen-thawed and sex-sorted frozen-thawed sperm.     

Determination of genetic relationships among five indigenous Chinese goat breeds with six microsatellite markers

Microsatellite variation was analyzed in five Chinese indigenous goat breeds, which include four Cashmere breeds (Tibetan, Neimonggol, Liaoning, Taihang) and one Hubei local breed (Matou) used for meat production. Five ovine and one bovine microsatellites, selected from eight ovine microsatellites and five bovine microsatellites were suitable for use in this study. With these six microsatellites, allele frequencies, heterozygosity, polymorphism information content (PIC) and effective allele number were calculated. A neighbor-joining tree was constructed using Nei's standard genetic distance (1978). In the tree, Neimonggol and Liaoning were grouped together, then with Taihang; while Tibetan and Matou individually had their own branch. The genetic relationship of five breeds corresponds to their history and geographic origins.     

Movement heterogeneity of dugongs, Dugong dugon (Müller), over large spatial scales

Seventy dugongs were fitted with satellite PTTs and/or GPS transmitters in sub-tropical and tropical waters of Queensland and the Northern Territory, Australia. Twenty-eight of the 70 dugongs were also fitted with time-depth recorders. The dugongs were tracked for periods ranging from 15 to 551 days and exhibited a large range of individualistic movement behaviours; 26 individuals were relatively sedentary (moving < 15 km) while 44 made large-scale movements (> 15 km) of up to 560 km from their capture sites. Male and female animals, including cows with calves, exhibited large-scale movements (LSM; > 15 km). Body length of travelling dugongs ranged from 1.9 to 3 m. At least some of the movements were return movements to the capture location, suggesting that such movements were ranging rather than dispersal movements. LSMs included macro-scale regional movements (> 100 km) and meso-scale inter-patch local movements (15 to < 100 km) and were qualitatively different from tidally-driven micro-scale commuting movements between and within seagrass beds (< 15 km). The mean ± S.E. macro-scale movement distance per individual was 243.8 ± 35.4 km (N = 14 individuals that travelled > 100 km), with a mean ± S.E. travel time of 179.8 ± 29.0 h. The mean ± S.E. meso-scale movement distance per individual was 49.7 ± 3.3 km (N = 28 individuals that made movements of 15-100 km), with a mean ± S.E. travel time of 52.3 ± 7.1 h. LSMs were rapid and apparently directed (mean ± S.E. travel speeds for GPS tagged animals; meso-scale movements = 1.3 ± 0.11 km/h, min = 0.3, max = 3.0; macro-scale movements = 1.6 ± 0.16 km/h, min = 0.8, max = 1.3). Tracked dugongs rarely travelled far from the coast (mean ± S.E. max distance = 12.8 ± 1.3 km). Dive profiles from the time-depth recorders suggest that dugongs make repeated deep dives while travelling rather than remaining at the surface, increasing their likelihood of capture in bottom set gill nets. Some animals caught in the high latitude limits of the dugongs' range on the Australian east coast in winter apparently undertook long distance movements in response to low water temperatures, similar to migrational movements by Florida manatees. Our findings that dugongs frequently undertake macro-scale movements have implications for management at a range of scales, and strengthen the aerial survey and genetic evidence for management and monitoring at ecological scales that cross jurisdictions.     

Multivariate characterization of morphological traits in Burkina Faso sheep

A total of 6440 female sheep from Burkina Faso were scored for seven body measurements and four qualitative morphological traits. Sampling included the three main environmental areas and sheep breeds of Burkina Faso: the Sahel area (Burkina-Sahel sheep), the Sudan-Sahel area (Mossi sheep) and the Sudan area (Djallonké sheep). Canonical analyses showed that differences in body measurements between the Sudan and the Sudan-Sahel sheep were small even though most body traits showed higher average values in the Burkina-Sahel sheep: the shortest Mahalanobis distance was found between the Sudan and the Sudan-Sahel populations (1.54), whilst that between the Sudan and the Sahelian populations was the largest (7.88). Discriminant analysis showed that most Sudan (Djallonké) individuals (60.85%) were classified as Sudan-Sahel (Mossi) individuals whilst most Burkina-Sahel individuals were classified into their environmental area of sampling (89.46%). Correspondence analyses indicated that the Burkina-Sahel sheep population clustered together with dropping ears, black and brown colour patterns and presence of wattles, the Sudan sheep were closely associated with long hair and vertical and curled ears and that the Sudan-Sahel sheep did not have clear associations with qualitative phenotypic traits. At the morphological level, the Sudan-Sahel (Mossi) sheep population can be considered a geographical subpopulation belonging to the Djallonké breed, showing some particularities, namely larger body size, due to the particular environmental condition of the area in which it is managed and a continuous gene flow from Sahelian sheep, The information reported in this study will be the basis for the establishment of further characterization, conservation and selection strategies for Burkina Faso sheep.     

Mapping of the transcription start site (TSS) and identification of SNPs in the bovine neuropeptide Y (NPY) gene

Background

The domestic goat is one of the important livestock species of India. In the present study we assess genetic diversity of Indian goats using 17 microsatellite markers. Breeds were sampled from their natural habitat, covering different agroclimatic zones.

Results

The mean number of alleles per locus (NA) ranged from 8.1 in Barbari to 9.7 in Jakhrana goats. The mean expected heterozygosity (He) ranged from 0.739 in Barbari to 0.783 in Jakhrana goats. Deviations from Hardy-Weinberg Equilibrium (HWE) were statistically significant (P < 0.05) for 5 loci breed combinations. The D_A measure of genetic distance between pairs of breeds indicated that the lowest distance was between Marwari and Sirohi (0.135). The highest distance was between Pashmina and Black Bengal. An analysis of molecular variance indicated that 6.59% of variance exists among the Indian goat breeds. Both a phylogenetic tree and Principal Component Analysis showed the distribution of breeds in two major clusters with respect to their geographic distribution.

Conclusion

Our study concludes that Indian goat populations can be classified into distinct genetic groups or breeds based on the microsatellites as well as mtDNA information.     

Genetic diversity in the Churra tensina and Churra lebrijana endangered Spanish sheep breeds and relationship with other Churra group breeds and Spanish mouflon

The aim of the present study was to estimate the genetic intra-breed variability of Churra tensina and Churra lebrijana endangered breeds and to establish genetic relationships with Churra, Latxa and Merino breeds, as well as Spanish mouflon, by using 28 microsatellite markers, to provide useful information for their conservation. Allele frequencies and heterozygosity revealed high genetic variation in the two endangered breeds despite their small population size. Estimates of inbreeding coefficient (F_IS) were significant for all breeds studied, except for Churra lebrijana breed. The highest inbreeding coefficient (F_IS = 0.143) was found in the Spanish mouflon. Genetic differentiation tests (F_ST = 0.121) and assignment of individuals to populations indicated the existence of defined breed populations, and low genetic flow between these breeds. The highest pairwise Reynolds distance (D_R) values were observed between Mouflon and the domestic sheep breeds. Considering only domestic sheep breeds, the Churra lebrijana breed showed the highest pairwise D_R values_. The lowest values were found between Latxa and the other domestic sheep, except for Churra lebrijana. Results of pairwise D_R values, as well as phylogenetic tree and bottleneck analysis showed an important genetic isolation of the Churra lebrijana breed from the other Churra types, and genetic signatures of a demographic bottleneck. Finally, structure analysis of populations detected a population subdivision in the Latxa sheep breed. In conclusion, this study presents valuable insight into the existing genetic variability of two Spanish endangered breeds, as well as the first study in Spanish mouflon based on microsatellite analysis. The high degree of variability demonstrated in Churra tensina and Churra lebrijana implies that these populations are rich reservoirs of genetic diversity.     

Measuring genetic distances between breeds: use of some distances in various short term evolution models

Many works demonstrate the benefits of using highly polymorphic markers such as microsatellites in order to measure the genetic diversity between closely related breeds. But it is sometimes difficult to decide which genetic distance should be used. In this paper we review the behaviour of the main distances encountered in the literature in various divergence models. In the first part, we consider that breeds are populations in which the assumption of equilibrium between drift and mutation is verified. In this case some interesting distances can be expressed as a function of divergence time, t, and therefore can be used to construct phylogenies. Distances based on allele size distribution (such as (δμ)² and derived distances), taking a mutation model of microsatellites, the Stepwise Mutation Model, specifically into account, exhibit large variance and therefore should not be used to accurately infer phylogeny of closely related breeds. In the last section, we will consider that breeds are small populations and that the divergence times between them are too small to consider that the observed diversity is due to mutations: divergence is mainly due to genetic drift. Expectation and variance of distances were calculated as a function of the Wright-Malécot inbreeding coefficient, F. Computer simulations performed under this divergence model show that the Reynolds distance [57]is the best method for very closely related breeds.     

The analysis of microsatellites and compound microsatellites in 56 complete genomes of Herpesvirales

Simple sequence repeats (SSRs), or microsatellites, are special DNA/RNA sequences with repeated unit of 1–6 bp. The genomes of Herpesvirales have many repeating structures, which is an excellent system to study the evolution and roles of microsatellites and compound microsatellites in viruses. Therefore, 56 genomes of Herpesvirales were selected and the occurrence, composition and complexity of different repeats were investigated in the genomes. A total of 63,939 microsatellites and 5825 compound microsatellites were extracted from 56 genomes. It found that GC content has a significant strong correlation with both the counts of microsatellites (CM) and the counts of compound microsatellites (CCM). However, genome size has a moderate correlation only with CM and almost no correlation with CCM. The compound microsatellites occurring in genic regions are obviously more than that in intergenic regions. In general, the number of compound microsatellite decreases with the increase of complexity (C) (the count of individual microsatellites being part of a compound microsatellite) and the complexity hardly exceeds C = 4. The vast majority of compound microsatellites exist in intergenic regions, when C ≥ 10. The distributions of SSRs tend to be organism-specific rather than host-specific in herpesvirus genomes. The diversity of microsatellites and compound microsatellites may be helpful for a better understanding of the viral genetic diversity, genotyping, and evolutionary biology in herpesviruses genomes.     

Characterization of bovine MHC DRB3 diversity in Latin American Creole cattle breeds

In cattle, bovine leukocyte antigens (BoLAs) have been extensively used as markers for diseases and immunological traits. However, none of the highly adapted Latin American Creole breeds have been characterized for BoLA gene polymorphism by high resolution typing methods. In this work, we sequenced exon 2 of the BoLA class II DRB3 gene from 179 cattle (113 Bolivian Yacumeño cattle and 66 Colombian Hartón del Valle cattle breeds) using a polymerase chain reaction sequence-based typing (PCR-SBT) method. We identified 36 previously reported alleles and three novel alleles. Thirty-five (32 reported and three new) and 24 alleles (22 reported and two new) were detected in Yacumeño and Hartón del Valle breeds, respectively. Interestingly, Latin American Creole cattle showed a high degree of gene diversity despite their small population sizes, and 10 alleles including three new alleles were found only in these two Creole breeds. We next compared the degree of genetic variability at the population and sequence levels and the genetic distance in the two breeds with those previously reported in five other breeds: Holstein, Japanese Shorthorn, Japanese Black, Jersey, and Hanwoo. Both Creole breeds presented gene diversity higher than 0.90, a nucleotide diversity higher than 0.07, and mean number of pairwise differences higher than 19, indicating that Creole cattle had similar genetic diversity at BoLA-DRB3 to the other breeds. A neutrality test showed that the high degree of genetic variability may be maintained by balancing selection. The F_ST index and the exact G test showed significant differences across all cattle populations (F_ST = 0.0478; p < 0.001). Results from the principal components analysis and the phylogenetic tree showed that Yacumeño and Hartón del Valle breeds were closely related to each other. Collectively, our results suggest that the high level of genetic diversity could be explained by the multiple origins of the Creole germplasm (European, African and Indicus), and this diversity might be maintained by balancing selection.     

Fat body catalase activity as a biochemical index for the recognition of thermotolerant breeds of mulberry silkworm, Bombyx mori L.

The fifth instar larvae of the silkworm Bombyx mori L. were exposed to selected high temperatures (35 and 40 °C) in order to understand the changes in the level of catalase activity in the three tissues of fat body, midgut and haemolymph of the five selected bivoltine breeds and their 9 quantitative traits, namely larval weight, cocoon weight, shell weight, shell ratio, filament length, filament weight, denier, renditta and effective rearing rate (ERR), also the correlation between them under high temperature conditions were examined. Catalase activity resulting in fat body revealed a positive correlation between the control (28±1 °C) and 40±1 °C. The CSR₂ breed showed the most level of thermotolerance and catalase activity, compared with the CSR₄, JROP, NB₄D₂ and KA breeds. It was found that the level of catalase activity in fat body may be a reliable biochemical index to recognize thermotolerant breeds in order to develop resistant hybrids for tropical areas.     

Cryobanking as tool for conservation of biodiversity: effect of brown trout sperm cryopreservation on the male genetic potential

Sperm cryobanking could be a good alternative to breeding in captivity in order to preserve genetic diversity. Sperm from two well-characterized brown trout populations originating from two river basins in the Northwest of Spain (Esla and Duerna), both threatened by extinction, was cryopreserved. In order to determine whether a sperm cryobank is the best option for preserving genetic profiles, cell viability, chromatin fragmentation, fertility and genetic variability of the offspring obtained with fresh and frozen sperm, were analyzed. Sperm viability was not reduced by freezing (87.0 ± 3.32% to 77.9 ± 3.59% and 77.6 ± 6.53% to 76.6 ± 2.61% in fresh and frozen sperm from Esla and Duerna, respectively). The percentage of fragmented DNA increased after freezing in spermatozoa from Esla males (from 4.7 ± 0.23% to 6.0 ± 0.28%), but not those from Duerna males.After freezing/thawing, the percentage of eyed embryos drops from 66.8 ± 6.77% to 16.1 ± 3.46% and from 50 ± 8.97% to 11.5 ± 2.50% in the Esla and Duerna basins, respectively. This reduction indicates that many spermatozoa have lost their ability to contribute to embryo development and this loss is not related to either spermatozoa viability or the DNA integrity. Genotypic determination by microsatellite analysis showed that frozen/thawed sperm provided offspring with a similar genetic profile to unfrozen milt, demonstrating the accuracy of the cryopreservation procedure.Taking into account the prolificacy of this species, even a low rate of success of fry after cryopreservation, could provide enough individuals to recover stable populations without altering the genetic profiles of the preserved strains. Therefore, cryopreservation is considered a safe, simple and cheap technology for gene banking in the analyzed brown trout populations.     

Genetic diversity of the endangered and endemic species Psathyrostachys huashanica natural populations using simple sequence repeats (SSRs) markers

Psathyrostachys huashanica Keng., a species endemic to China, is only distributed in Huashan Mountain in Shaanxi Province. It has been listed as “national first-class protected rare species.” In this study, the microsatellites of barley were used to analyze genetic diversity of P. huashanica populations sampled from three valleys (Huangpu, Xian and Huashan Valleys) in Mt. Huashan. A total of 33 alleles of 11 loci were detected from 266 individuals. The observed average number of alleles (A) is 2.75; the effective number of alleles (Ae) is 1.67. The percentage of polymorphic loci (PPB) is 58.33% in Huangpu Valley, 75% in Xian Valley, 83.33% in Huashan Valley, and the total PPB is 83.33%. About 77.6% of (F_ST = 0.324) genetic diversity was observed within the subpopulations. Genetic differentiation within each subpopulations was higher than that among the subpopulations. Mean genetic distance is 0.17 (range: 0.010–0.401). Correlation analysis detected significant correlation between genetic distance and vertical distance of altitude in Huashan Valley. Differentiation mainly occurred between the higher altitude subpopulations and the lower altitude subpopulations, suggesting that altitude might be the major factor that restricted the gene flow between different altitude subpopulations and resulted in differentiation of subpopulations.