Single horny Lizard md

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Try out PMC Labs and tell us what you think. Learn More. The following information was supplied regarding data availability:. The raw nuclear microsatellite genotypes, mitochondrial control region haplotypes, GPS coordinates, 16 sampling sites, and proportion of ancestry as determined by STRUCTURE for all individuals, the alignment of unique haplotypes for the mitochondrial ND4 region and the alignment of unique haplotypes for the mitochondrial control region are all available in the Supplemental Files.

Since the s, this species has Single horny Lizard md extirpated from much of its eastern range and has suffered declines and local extinctions elsewhere, primarily due to habitat loss. Plans are underway to use captive breeding to produce large s of Texas horned lizards for reintroduction into areas that were historically occupied by this species and that currently have suitable habitat. We used mitochondrial markers and nuclear microsatellite markers to determine levels of genetic diversity and population structure in Texas horned lizards sampled from across Texas and some neighboring states to help inform these efforts.

Texas horned lizards still retain high genetic diversity in many parts of their current range. We found two highly divergent mitochondrial clades eastern and western and three major genetic groupings at nuclear microsatellite loci: a west group corresponding to the western mitochondrial clade and north and south groups within the eastern mitochondrial clade. We also found some evidence for human-mediated movement between these genetic clusters that is probably related to the historical importance of this species in the pet trade and as an iconic symbol of the southwestern United States.

We do not know, however, if there are fitness costs associated with admixture especially for the western and eastern clades or if there are fitness costs to moving these lizards into habitats that are distinctly different from their ancestral areas.

If present, either one or both of these fitness costs would decrease the effectiveness of reintroduction efforts.

Single horny Lizard md

We therefore recommend that reintroduction efforts should maintain current genetic structure by restricting breeding to be between individuals within their respective genetic clusters, and by reintroducing individuals only into those areas that encompass their respective genetic clusters. This cautionary approach is based on the strong divergence between genetic groupings and their correspondence to different ecoregions.

The loss of suitable native habitat to agriculture and urbanization, and the overexploitation of populations have been the largest drivers of the decline of many species Maxwell et al. Reintroduction and reinforcement programs try to reduce these effects by returning a species to an area from which it became locally extinct or by increasing the s of individuals in small populations IUCN, ; Seddon, A sufficient of individuals with high genetic diversity should be utilized in these efforts to reduce the potential for inbreeding depression and enhance the ability of a population to adapt to changing environmental conditions Johnson et al.

Additionally, it may also be advisable to prevent mixing of individuals from populations that are ecologically and genetically divergent, to reduce the chances of outbreeding depression Frankham et al. Understanding the population genetic structure of a species can inform these efforts by identifying appropriate source populations, defining management units, and identifying populations that have high genetic diversity Weeks et al.

Texas horned lizards Phrynosoma cornutum belong to a specialized group of lizards Phrynosoma that are endemic to North America. They have a variety of adaptations for living in dry environments and for specializing on a diet of large venomous ants e. Texas horned lizards have an extensive range in North America and cover a of different ecoregions Price, The geographic extent of these clades is not clear, however, due to a lack of comprehensive sampling in past studies.

Texas horned lizards are generally sedentary and aspects of their life history and anatomy suggest dispersal is relatively limited Sherbrooke,which could result in strong population structure for this species. On the other hand, anecdotal s suggest that these lizards have been moved extensively by the pet trade and individual collectors Price,leading to more population homogenization than might be expected from natural dispersal.

Other possible factors include the introduction of red fire ants Solenopsis invicta which can prey on the eggs and young of horned lizards, the loss of harvester ants Pogonomyrmex spp. Currently the species is listed as threatened in Texas due to the declines, but globally it is classified as least concern by the IUCN since the species is still common in the more western and southern parts of its range Hammerson, Widespread interest by private landowners and the Texas Parks and Wildlife Department has led to a plan in which Texas zoos will captive breed large s of individuals to be reintroduced into areas that historically had Texas horned lizards and that currently have suitable habitat.

To aid in this effort, we used mitochondrial markers and nuclear microsatellite markers to determine levels of genetic diversity and population structure of Texas horned lizards across Texas and some neighboring states. Species Single horny Lizard md Texas horned lizards, which occur over large geographic areas, inhabit a range of habitats, and have relatively low dispersal capabilities may have an increased chance of developing regional adaptations Lenormand, We therefore also ask if genetic subdivisions are related to ecoregions, which could potentially indicate the presence of regionally-adapted units.

These will be used to determine the most appropriate source populations for reintroduction efforts and to provide recommendations for how captive populations should be managed. The neutral genetic patterns described in this study will also help inform future planned studies of adaptive genetic diversity in this species. A of volunteers collected Texas horned lizard tissue samples across Texas, New Mexico, and Colorado between and Fig.

While most of these samples were collected using the cloacal swab method described in Williams et al. The following day, a half volume of 7. Then 0. For each sample, 0. Genotypes were scored and binned using Genemapper 5. Reactions were cycled in an ABI thermal cycler. Sequences were trimmed, edited, and put into contigs using Sequencher 4. The cryptic nature and low density of Texas horned lizards in most places made it difficult to find large s of individuals from single Single horny Lizard md.

We grouped lizards into these sites because we were interested in estimating the genetic diversity present in protected areas such as Wildlife Management Areas and State Parks where individuals might be captured for future captive breeding purposes. The coordinates for these sites were the centroids of the sampled lizard locations. For these 16 sites, we used GenAlEx 6. We used sequential Bonferroni correction to determine ificance for these tests. We used these corrected values to test for isolation-by-distance using the Mantel test in GenAlEx. s are, 1, Brewster Co. New Mexico.

We assumed admixture and correlated allele frequencies with no location prior and set the burn-in to 10 Single horny Lizard md iterations and ran the MCMC Monte Carlo Markov Chain for 10 6 iterations. We chose this value since similar cut-off values have been used in a of other studies Barilani et al. We used GenAlEx to calculate the frequency of haplotypes and haplotype diversity h of the control region for the 16 sampling sites mentioned above. We constructed single gene trees for both ND4 and the control region due to the difference in sampling for each marker.

Single horny Lizard md

These models were then used to create maximum likelihood trees in MEGA using the nearest-neighbor-interchange and a strong branch swap filter. Bootstrap values were calculated using 1, replicates. Bayesian analyses using MrBayes 3. We used DnaSP 6.

Single horny Lizard md

We calculated tau in Arlequin 3. We used a substitution rate of 0. Most loci across the 16 sampling sites were in Hardy-Weinberg equilibrium and all loci were in genotypic linkage equilibrium.

Single horny Lizard md

There were four loci that gave evidence of null alleles at one site each and another locus that had evidence for null alleles at two sites Table S1. We found eight allele errors across 1, alleles in the 55 individuals we re-genotyped for an error rate of 0.

These errors occurred across five loci per locus error rates for these five loci ranged from 0. We corrected for null alleles when calculating F ST ; however, this made virtually no difference in the observed patterns F ST values generally only decreased by 0. Population differentiation was modest but ificant with a global F ST of 0. Most pairwise F ST comparisons were ificantly different from zero except for 23 comparisons which were all between sites within the cluster of 11 sites in the PCA Table S2.

Colors correspond to populations determined by STRUCTURE: dark red, west; light blue, south; dark grey, north, dark grey and red hatch marks on 1 indicates a mix of north and west. s are sampling sites: 1, Brewster Co. At increasing levels of K 4—10new clusters were simply added as admixture in the large north population. Sub-clustering the west population revealed two clusters, one composed of west individuals and another population from Brewster Co. Sub-clustering the north population did not reveal more populations.

Individual lizards are organized by geographic sampling location, starting with the most western locations on the left and then moving to more northern locations and then southern locations. Shading has been added to illustrate the ecoregions with the highest ancestry in each genetic cluster West, North, South. The remaining two individuals were admixed between all three populations; one was found in southern Texas whereas the other was found in northern Texas.

Admixed individuals with north and west ancestry were found in Brewster Co. Haplotype diversity at the control region was high with a total of 86 haplotypes found across all individuals. Site column is the corresponding to map locations; cluster column is the population determined by STRUCTURE to which each site belongs: W, west; N, north; S, south; N is of individuals sampled at each site; H is of haplotypes; H R is haplotype richness standardized for 10 individuals; and Single horny Lizard md is haplotype diversity.

The control region gene tree revealed two clades between haplotypes found in western areas New Mexico and far Single horny Lizard md Texas and more eastern areas Fig. For the control region, there were a total of ten unique haplotypes in the western clade and 76 haplotypes in the eastern clade. There was an average of 3. Within Brewster Co. Individuals with the eastern haplotypes had microsatellite ancestry within the north, south, and west populations. Control region haplotypes were, however, largely unique to the geographic regions encompassed by the three main nuclear microsatellite populations west, north, and south as indicated by the colored symbols in Fig.

Single horny Lizard md

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Population genetic structure of Texas horned lizards: implications for reintroduction and captive breeding