scholarly journals Microsatellite genotyping from faeces of Lontra longicaudis from southern Brazil

2009 ◽  
Vol 99 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Laura I. Weber ◽  
Cintia G. Hildebrand ◽  
Anderson Ferreira ◽  
Gustavo Pedarassi ◽  
José A. Levy ◽  
...  

A genetic study of the neotropical river otter Lontra longicaudis (Olfers, 1818), which has an unknown conservation status, was carried out at the Taim Ecological Station and the margins of the Vargas stream, Rio Grande do Sul, southern Brazil. Faecal samples were collected, and DNA was extracted using a silica-guanidine method. Five microsatellite loci were amplified using PCR with heterologous primers previously described for Lutra lutra (Linnaeus, 1758). Sixteen faecal samples out of 29 from Taim and 11 out of 14 from Vargas stream margins contained enough DNA for genetic analysis. A total of 49 different alleles were found at both localities, from which 18 were exclusively found in individuals from Taim and 17 were exclusives from Vargas individuals. The most common allele was the same at both locations for three loci (Lut715, Lut733, and Lut818). A high level of genetic diversity was found at both sites (NeTaim=4.1, HoTaim=0.299, HeTaim=0.681; NeVargas=4.9, HoVargas=0.355, HeVargas=0.724), being higher at the Vargas stream site. A high and significant level of heterozygote deficiency was observed at most loci according to the χ2 test. The homogeneity χ2 test (P<0.001) showed that there were significant differences in the allele frequencies between the two locations. Genotyping for more than one locus was possible in 81.5% of samples, from which only 37% were possible to genotype for more than three loci. A low degree of relatedness was found among individuals from Taim (R=0.055±0.310), but an even lower value of relatedness was found at the Vargas site (R= -0.285±0.440). The significant degree of differentiation (I=0.890; F ST=0.059) found between Taim and Vargas individuals suggests that there is more than one population of otters in the southern extreme of Brazil, which probably are associated with the water body systems found in this region, the Mirim and the Caiuvá/Flores/Mangueira Lagoons. The high genetic diversity and low relatedness found at the Vargas stream, lead us to believe that the Vargas stream may be acting as a corridor between these water bodies for otter dispersion.

2017 ◽  
Vol 65 (2) ◽  
pp. 173-184 ◽  
Author(s):  
Leila Ben Said ◽  
Raoudha Dziri ◽  
Nadia Sassi ◽  
Carmen Lozano ◽  
Karim Ben Slama ◽  
...  

In order to investigate the possible role of dogs and cats in the carriage and potential dissemination of resistant enterococci, seventy faecal samples from dogs and cats were tested for enterococci. Fifty-eight enterococci were recovered. Isolates were identified as Enterococcus faecium (n = 31) and E. faecalis (n = 14) E. durans (n = 6), E. casseliflavus (n = 2), E. hirae and E. gallinarum (2 isolates each). Enterococcal isolates showed resistance to ciprofloxacin (n = 35), erythromycin (n = 31), tetracycline (n = 25), kanamycin (n = 15), streptomycin (n = 13), pristinamycin (n = 11), gentamicin (n = 10), chloramphenicol (n = 8), and linezolid (n = 6). The gene erm(B) was detected in 22 out of 31 erythromycin-resistant enterococci. All tetracycline-resistant enterococci carried tet(M) and/or tet(L) genes. The gene aac(6′)-Ie-aph(2″)-Ia was identified in five of high-level gentamicin-resistant isolates, the genes aph(3′)-IIIa and/or aac(6′)-Ie-aph(2″)-Ia in eleven high-level kanamycin-resistant isolates and the gene ant(6)-Ia in eleven high-level streptomycin-resistant isolates. Only one strain harboured cat(A) gene, and five strains contained vat(E) or vat(D) genes. Virulence genes gel(E) (21 strains), esp (11 strains) and cylA/cylB (5 strains) were detected. High genetic diversity was demonstrated among E. faecium isolates by pulsed-field gel electrophoresis (PFGE). Dogs and cats can be carriers of antibiotic-resistant enterococci in their faeces that could shed into the household environment.


2021 ◽  
Author(s):  
E. Lamalakshmi Devi ◽  
Umakanta Ngangkham ◽  
Akoijam Ratankumar Singh ◽  
Bhuvaneswari S ◽  
Konsam Sarika ◽  
...  

Abstract North- Eastern parts of India fall under Eastern Himalayan region and it is a diversity hotspot of many crops including maize. Evaluation of genetic diversity is required to tape the potentiality of genetic resources in any crop improvement programmes. In the present study, genetic diversity at fifty two microsatellite markers were conducted in 30 early maize inbreds developed from local landraces of NE India. Genetic diversity analysis revealed a total of 189 alleles with a mean of 3.63 alleles/ locus. The allele size ranged from 50 bp (phi 036) to 295 bp (p 101049) which revealed a high level of genetic diversity among the loci. The PIC among the 30 genotypes ranged from 0.17 (umc 1622) to 0.76 (umc 1153) with an average value of 0.49. The value of Expected Heterozygosity (HExp) ranged from 0.19 to 0.80 with an average of 0.57, whereas the Observed Heterozygosity (HObs) ranged from 0 to 0.89 with a mean of 0.14.The genetic dissimilarity between the genotype pairs ranged from 0.40 to 0.64 with a mean value of 0.57. Cluster analysis grouped the 30 inbreds into distinct three sub-clusters. Similarly, population structure and principal coordinate analysis) analysis also classified the 30 inbred lines into three-subpopulations. AMOVA revealed that 6% of total variance is due to differences among populations, while 94% of total molecular variance is accounted by within populations. Marker-trait associations showed a total of twelve SSR markers significantly associated with seven agronomic traits. From the present finding, these results show that the thirty maize inbreds have high genetic diversity which would be useful for choosing promising parents and for making cross combination based on genetic distance and clustering for genetic improvement programmes of maize.


2015 ◽  
Vol 122 (1-4) ◽  
pp. 1-6
Author(s):  
Jeffrey T Ploegstra ◽  
Brittany de Ruyter ◽  
Tony Jelsma

Isolated in scattered remnants, less than 0.1% of Iowa's original tallgrass prairie remains. The small populations remaining are at risk for reduced genetic diversity, inbreeding depression, and outbreeding depression. In light of these concerns, we used microsatellite analysis to assess the genetic structure of butterfly milkweed (Asclepias tuberosa) populations on prairie remnants in northwest Iowa. We compared remnant populations with a restoration population at Dordt College in Sioux Center, Iowa, and with an Oklahoma seed source. Microsatellites identified for use in common milkweed (Asclepias syriaca) had sufficient polymorphism information content (PIC) across the butterfly milkweed (A. tuberosa) populations sampled (mean PIC = 0.624). The FIS values indicated a lack of inbreeding (mean FIS = −0.1455) even in the commercially expanded seed. The pairwise FST values showed a low degree of differentiation among the remnants (mean FST = 0.0453) but a moderate degree (mean FST = 0.105) of differentiation when comparing the remnants to the Dordt restoration or to seed from Oklahoma. Despite massive loss and fragmentation of the tallgrass prairie, our microsatellite analysis revealed no evidence of inbreeding in A. tuberosa. However, evidence of genetic differentiation suggests that effort should be made to preserve the diversity still present. Seed expansion efforts appear to have had minimal impact on overall genetic diversity, although the diversity in particular selectable traits may be reduced. The differences between the genetics of the propagated seed at the Dordt restoration and the Oklahoma seed when compared to native remnants support the usefulness of source-identified seed.


2021 ◽  
Vol 102 (8) ◽  
Author(s):  
Jie Zhu ◽  
Mingpu Qi ◽  
Chuanwen Jiang ◽  
Yongchong Peng ◽  
Qingjie Peng ◽  
...  

Bovine astrovirus (BoAstV) belongs to genus Mamastravirus (MAstV). It can be detected in the faeces of both diarrhoeal and healthy calves. However, its prevalence, genetic diversity, and association with cattle diarrhoea are poorly understood. In this study, faecal samples of 87 diarrhoeal and 77 asymptomatic calves from 20 farms in 12 provinces were collected, and BoAstV was detected with reverse transcription-polymerase chain reaction (RT-PCR). The overall prevalence rate of this virus in diarrhoeal and asymptomatic calves was 55.17 % (95 % CI: 44.13, 65.85 %) and 36.36 % (95 % CI: 25.70, 48.12 %), respectively, indicating a correlation between BoAstV infection and calf diarrhoea (OR=2.15, P=0.024). BoAstV existed mainly in the form of co-infection (85.53 %) with one to five of nine viruses, and there was a strong positive correlation between BoAstV co-infection and calf diarrhoea (OR=2.83, P=0.004). Binary logistic regression analysis confirmed this correlation between BoAstV co-infection and calf diarrhoea (OR=2.41, P=0.038). The co-infection of BoAstV and bovine rotavirus (BRV) with or without other viruses accounted for 70.77 % of all the co-infection cases. The diarrhoea risk for the calves co-infected with BoAstV and BRV was 8.14-fold higher than that for the calves co-infected with BoAstV and other viruses (OR=8.14, P=0.001). Further, the co-infection of BoAstV/BRV/bovine kobuvirus (BKoV) might increase the risk of calf diarrhoea by 14.82-fold, compared with that of BoAstV and other viruses (OR=14.82, P <0.001). Then, nearly complete genomic sequences of nine BoAstV strains were assembled by using next-generation sequencing (NGS) method. Sequence alignment against known astrovirus (AstV) strains at the levels of both amino acids and nucleotides showed a high genetic diversity. Four genotypes were identified, including two known genotypes MAstV-28 (n=3) and MAstV-33 (n=2) and two novel genotypes designated tentatively as MAstV-34 (n=1) and MAstV-35 (n=3). In addition, seven out of nine BoAstV strains showed possible inter-genotype recombination and cross-species recombination. Therefore, our results increase the knowledge about the prevalence and the genetic evolution of BoAstV and provide evidence for the association between BoAstV infection and calf diarrhoea.


2020 ◽  
Author(s):  
Mayara Delagnelo Medeiros ◽  
Daniel Galiano ◽  
Bruno Busnello Kubiak ◽  
Paula Angélica Roratto ◽  
Thales Renato Ochotorena de Freitas

Abstract Endemic, small range species are susceptible to environmental changes and landscape modification. Understanding genetic diversity and distributional patterns is important for implementation of effective conservation measures. In this context, genetic diversity was evaluated to update the conservation status of an endemic tuco-tuco, Ctenomys ibicuiensis. Phylogeographic and population genetic analyses of mitochondrial DNA and microsatellite loci were carried out using 46 individuals sampled across the species’ distribution. Ctenomys ibicuiensis presented moderate to high genetic diversity and highly structured populations with low levels of gene flow and isolation by distance. Anthropogenic landscape changes threaten this restricted-range tuco-tuco. Considering its limited geographic distribution and highly structured populations with low gene flow, we consider C. ibicuiensis to be at significant risk of extinction.


2015 ◽  
Vol 43 (1) ◽  
pp. 86-95 ◽  
Author(s):  
Imane MEDOUKALI ◽  
Ines BELLIL ◽  
Douadi KHELIFI

As part of the evaluation and enhancement of genetic resources, morphological and isozyme variability within and among 169 accessions, representing 14 species of the genus Medicago L. collected in northern Algeria, was assessed using twelve quantitative traits and two enzymatic systems. Phenotype frequencies were scored in six enzyme zones to determine isozyme variability within and among populations. The data analysis resolved a high level of genetic diversity. Ten morphometric characteristics contributed to the discrimination of the species. The relationship between the collection site environment and phenotypic characteristics was also studied. Esterase (EST) enzyme system was more polymorphic than glutamate oxaloacetate transaminase (GOT) system. Were scored 2 zones with 10 bands and 21 phenotypes for GOT (glutamate oxaloacetate transaminase) and 4 zones with 22 bands and 71 phenotypes for EST (esterase) Polymorphism index and Jaccard’s genetic distances revealed the existence of a high genetic diversity within and among the studied populations. The annual species M. polymorpha presented an intraspecific polymorphism index of 0.57, which was higher than all other species indices. Clustering of the species based on isozyme markers was in agreement with taxonomic criteria and showed no significant correlation with morphological characteristics. Conservation programs should take into account the level of genetic diversity within and between populations revealed by isozyme markers.


2011 ◽  
Vol 57 (6) ◽  
pp. 717-724 ◽  
Author(s):  
Jiandong Yang ◽  
Zhihe Zhang ◽  
Fujun Shen ◽  
Xuyu Yang ◽  
Liang Zhang ◽  
...  

Abstract Understanding present patterns of genetic diversity is critical in order to design effective conservation and management strategies for endangered species. Tangjiahe Nature Reserve (NR) is one of the most important national reserves for giant pandas Ailuropoda melanoleuca in China. Previous studies have shown that giant pandas in Tangjiahe NR may be threatened by population decline and fragmentation. Here we used 10 microsatellite DNA markers to assess the genetic variability in the Tangjiahe population. The results indicate a low level of genetic differentiation between the Hongshihe and Motianling subpopulations in the reserve. Assignment tests using the Bayesian clustering method in STRUCTURE identified one genetic cluster from 42 individuals of the two subpopulations. All individuals from the same subpopulation were assigned to one cluster. This indicates high gene flow between subpopulations. F statistic analyses revealed a low FIS-value of 0.024 in the total population and implies a randomly mating population in Tangjiahe NR. Additionally, our data show a high level of genetic diversity for the Tangjiahe population. Mean allele number (A), Allelic richness (AR) and mean expected heterozygosity (HE) for the Tangjiahe population was 5.9, 5.173 and 0.703, respectively. This wild giant panda population can be restored through concerted effort.


1993 ◽  
Vol 41 (3) ◽  
pp. 355 ◽  
Author(s):  
J Playford ◽  
JC Bell ◽  
GF Moran

A study of allozyme variation in Acacia melanoxylon R. Br. in 27 populations from across the geographic range of the species indicated high genetic diversity compared to other Australian trees and plants generally. Clines of increasing genetic variability with increasing latitude were found for four measures of genetic diversity. Most of the genetic diversity is found within populations but there was an unusually high level of the variation between populations (37.7%). A distinct genetic separation between the northern and southern populations was located approximately at the Hunter River region, where there is also a disjunction in the distribution of the species. The Nei (1978) genetic distance between these populations within this species is larger than observed between some plant species. Clearly the species has evolved separately in the two regions for a considerable time.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1893
Author(s):  
Ana Maria Figueira Gomes ◽  
David Draper ◽  
Pedro Talhinhas ◽  
Paula Batista Santos ◽  
Fernanda Simões ◽  
...  

Cowpea is a multiple-purpose drought-tolerant leguminous pulse crop grown in several dry tropical areas. Its domestication center is thought to be East or West Africa, where a high level of genetic diversity is apparently still found. However, detailed genetic information is lacking in many African countries, limiting the success of breeding programs. In this work, we assessed the genetic variation and gene flow in 59 Vigna unguiculata (cowpea) accessions from 10 landraces spanning across six agro-ecological zones of Mozambique, based on nuclear microsatellite markers. The results revealed the existence of high genetic diversity between the landraces, even in comparison to other world regions. Four genetic groups were found, with no specific geographic pattern, suggesting the presence of gene flow between landraces. In comparison, the two commercial varieties had lower values of genetic diversity, although still close to the ones found in local landraces. The high genetic diversity found in Mozambique sustains the importance of local genetic resources and farm protection to enhance genetic diversity in modern varieties of cowpea worldwide.


Botany ◽  
2010 ◽  
Vol 88 (8) ◽  
pp. 765-773 ◽  
Author(s):  
Ivandilson Pessoa Pinto de Menezes ◽  
Paulo Augusto Vianna Barroso ◽  
Lúcia Vieira Hoffmann ◽  
Valeska Silva Lucena ◽  
Marc Giband

Mocó cotton ( Gossypium hirsutum  L. race marie-galante (Watt) Hutch.) is a potential source of valuable alleles for breeding programs, mainly because of its great adaptability to semi-arid conditions. With the aim of quantifying mocó cotton genetic variability, 187 plants collected in the northeast of Brazil were evaluated using 12 microsatellite markers. A total of 62 alleles were amplified, ranging from three to eight polymorphic alleles per locus. Total genetic diversity was high (0.52), and when measured on a per state basis, was of 0.37 on average. The population showed a low level of heterozygozity (HO = 0.16), reflecting a high level of endogamy (FIS = 0.67). Phylogenetic analysis using the neighbor-joining method revealed that plants sampled in different states tended to cluster according to their geographic origin, except for those collected in the states of Paraíba and Rio Grande do Norte, which grouped together. Plants from the state of Piauí formed two groups, one with an apparent allelic contribution from G. barbadense, while the second group of plants was closer to those from the states of Paraíba and Rio Grande do Norte. Despite the high genetic diversity that was observed in the remaining populations, urgent conservation efforts should be undertaken, owing to the high level of endogamy and accelerated extinction process that characterizes these populations. Such efforts should focus on the collection and ex situ maintenance of representative genetic diversity.


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