conservation.arizona.edu - microsatellites

Phylogeographic and diversification patterns of the white-nosed coati T (Nasua narica): Evidence for south-to-north colonization

thackerk1 — Wed, 24 Jul 2019 00:13:21 +0000

Authors

Sergio F. Nigenda-Morales

Matthew E. Gompper

David Valenzuela

Anna R. Lay

Karen M. Kapheim

Christine Hass

Susan D. Booth-Binczik

Gerald A. Binczik

Ben T. Hirsch

Maureen McColgin

John L. Koprowski

Katherine McFadden

Robert K. Wayne

Klaus-Peter Koepfli

White-nosed coatis (Nasua narica) are widely distributed throughout North, Central, and South America, but the patterns of temporal and spatial diversification that have contributed to this distribution are unknown. In addition, the biogeographic history of procyonid species in the Americas remains contentious. Using sequences from three mitochondrial loci (Cytochrome b, NAHD5 and 16S rRNA; 2201 bp) and genotypes from 11 microsatellite loci, we analyzed genetic diversity to determine phylogeographic patterns, genetic structure, divergence times, and gene flow among Nasua narica populations throughout the majority of the species’ range. We also estimated the ancestral geographic range of N. narica and other procyonid species. We found a high degree of genetic structure and divergence among populations that conform to five evolutionarily significant units. The most southerly distributed population (Panama) branched off much earlier (∼3.8 million years ago) than the northern populations (< 1.2 million years ago). Estimated gene flow among populations was low and mostly northwards and westwards. The phylogeographic patterns within N. narica are associated with geographic barriers and habitat shifts likely caused by Pliocene-Pleistocene climate oscillations. Significantly, our findings suggest the dispersal of N. narica was south-to-north beginning in the Pliocene, not in the opposite direction during the Pleistocene as suggested by the fossil record, and that the most recent common ancestor for coati species was most likely distributed in South or Central America six million years ago. Our study implies the possibility that the diversification of Nasua species, and other extant procyonid lineages, may have occurred in South America.

Additional Information

Molecular Phylogenetics and Evolution

Date of publication:

2018

Topics

Procyonidae

mitochondrial haplotypes

microsatellites

evolutionary history

biogeographical methods White-nosed coatis

Research Categories

Natural History Population Ecology Sky Islands

Munroe, K.E., and J.L. Koprowski. 2011. Sociality, Bateman’s gradients and the polygynandrous genetic mating system of round-tailed ground squirrels (Xerospermophilus tereticaudus). Behavioral Ecology and Sociobiology. 65: 1811-1824.

thackerk1 — Tue, 23 Jul 2019 23:45:01 +0000

Authors

Karen E. Munroe

John L. Koprowski

Historically, most mammals have been classified as polygynous; although recent molecular evidence suggests that many mammals may be polygynandrous, particularly the ground-dwelling sciurids. We genotyped 351 round-tailed ground squirrels (Xerospermophilus tereticaudus) using seven microsatellite loci to determine paternity in 31 litters from 2004 to 2007. Polygyny was evident in all years except in 2007, when the population size was reduced. Multiple paternity occurred in the majority of litters (55%) with 2.5±0.26 sires/litter (n=31). Forty-nine percent of resident males (n = 114) sired offspring, and of males that sired offspring (n=56) 27% sired young in multiple litters in a single breeding season. Litter size was positively correlated with the number of sires. Through an indirect analysis of paternity, we found 21 litters (68%) with an average relatedness of 0.5 or less. Males had a greater opportunity for sexual selection (Is = 1.60) than females (Is = 0.40); Bateman’s gradient was also greater in males (1.07 ± 0.04, n = 56) than females (0.82 ± 0.08, n = 31). The mating system in round-tailed ground squirrels defined through genetic analyses and Bateman’s gradients is polygynandrous compared to the previously suggested polygynous mating system as established by behavioral observations and fits within the predictions of the ground squirrel sociality models. Upon evaluating the predictions of the sociality models among sciurid species, we found a negative relationship between the level of sociality with litter size and the average percentage of multiple paternity within a litter. Thus, recent genetic information and reclassification of mating systems support the predictions of the ground-dwelling squirrel sociality models.

Additional Information

Sociality, Bateman’s gradients, and the polygynandrous genetic mating system of round-tailed ground squirrels (Xerospermophilus

Date of publication:

2011

Topics

round-tailed ground squirrels

sociality

Arizona

polygynandry

multiple paternity

microsatellites

parentage analysis

Munroe, K. E., and J. L. Koprowski. 2014. Levels of social behaviors and genetic structure in a population of round-tailed ground squirrels (Xerospermophilus tereticaudus). Behavioral Ecology and Sociobiology 68:629-638.

thackerk1 — Tue, 23 Jul 2019 23:41:49 +0000

Authors

Karen E. Munroe

John L. Koprowski

Ground-dwelling sciurids exhibit a continuum of sociality and several models predict levels of sociality within this taxon. Models of ground squirrel sociality predict round- tailed ground squirrels (Xerospermophilus tereticaudus) to be solitary; however, previous behavioral studies suggest round-tailed ground squirrels have a matrilineal social structure. To resolve this discrepancy, we combined behavioral observations with genetic analyses of population structure. We assessed levels of agonistic and amicable behaviors combined with fine-scale population genetic structure of round-tailed ground squirrels in a multi-year study in AZ. Only 45 agonistic and 40 amicable interactions were observed between adults in over 137 h of observations. Overall rates of agonistic or amicable interactions between adults were low (≤0.69/h), with no relationship between relatedness of individuals and rates of either amicable or agonistic interactions. Interactions between juvenile littermates were predominantly amicable. Population substructure was not evident with Bayesian analyses, global or pairwise FST values; average relatedness among females was not different from males. However, in 2006, the year after a population reduction through targeted animal elimination, a population bottleneck was detected within at least five of seven loci. Contrary to previous behavioral studies, this population of round-tailed ground squirrels, although aggregated spatially, did not exhibit high levels of social behavior nor subpopulation genetic structure. Analyses of the genetic relationships and sociality along a continuum, particularly within aggregates of individuals, may lead to insights into the origin and maintenance of social behaviors by elucidating the mechanisms by which aggregates with intermediate social levels are formed and maintained.

Additional Information

Levels of social behaviors and genetic structure in a population of round-tailed ground squirrels (Xerospermophilus tereticaudus

Date of publication:

2014

Topics

round-tailed ground squirrels

Arizona

bottleneck

sociality

microsatellites

sciuridae

Genetic assessment of a bighorn sheep population expansion in the Silver Bell Mountains, Arizona

thackerk1 — Thu, 27 Jun 2019 21:33:26 +0000

Authors

John A. Erwin

Karla Vargas

Brian R. Blais

Kendell Bennett

Julia Muldoon

Sarah Findysz

Courtney Christie

James R. Heffelfinger

Melanie Culver

Background. The isolated population of desert bighorn sheep in the Silver Bell Mountains of southern Arizona underwent an unprecedented expansion in merely four years. We hypothesized that immigration from neighboring bighorn sheep populations could have caused the increase in numbers as detected by Arizona Game and Fish Department annual aerial counts.

Methods. We applied a multilocus genetic approach using mitochondrial DNA and nuclear microsatellite markers for genetic analyses to find evidence of immigration. We sampled the Silver Bell Mountains bighorn sheep before (2003) and during (2015) the population expansion, and a small number of available samples from the Gila Mountains (southwestern Arizona) and the Morenci Mine (Rocky Mountain bighorn) in an attempt to identify the source of putative immigrants and, more importantly, to serve as comparisons for genetic diversity metrics.

Results. We did not find evidence of substantial gene flow into the Silver Bell Mountains population. We did not detect any new mitochondrial haplotypes in the 2015 bighorn sheep samples. The microsatellite analyses detected only one new allele, in one individual from the 2015 population that was not detected in the 2003 samples. Overall, the genetic diversity of the Silver Bell Mountains population was lower than that seen in either the Gila population or the Morenci Mine population.

Discussion. Even though the results of this study did not help elucidate the precise reason for the recent population expansion, continued monitoring and genetic sampling could provide more clarity on the genetic demographics of this population.

Additional Information

PeerJ

Date of publication:

2018

Topics

bighorn sheep

population growth

microsatellites

mitochondrial DNA

migration

Silver Bell Mountains

Research Categories

Natural History Population Ecology Sky Islands Threatened and Endangered Species