Genetic diversity and structure among subspecies of white-tailed deer in Mexico

Available names for Rangifer (Mammalia, Artiodactyla, Cervidae) species and subspecies

Advancements in molecular and phylogenetic analysis have revealed the need for greater taxonomic resolution since Rangifer (Reindeer and caribou: Cervidae) was last revised in 1961. Recent literature shows that many of the subspecies and several species synonymised out of existence are, in fact, valid, some names have been misapplied, and new subspecies-level clades are in need of description. This paper reviews available names for recently defined ecotypes of reindeer and caribou in compliance with ICZN rules for zoological nomenclature.

An isolated white-tailed deer (Odocoileus virginianus) population on St. John, US Virgin Islands shows low inbreeding and comparable heterozygosity to other larger populations

This is the first study to document the genetic diversity of the white-tailed deer population on St. John, US Virgin Islands. The island population was founded by a small number of animals, has very limited hunting or predation, and recently experienced a reduction in size following an extended drought in 2015. DNA samples were collected from hair from 23 anesthetized adult deer (13 males, 10 females) ranging in age from 1 to 8 years (3.36 ± 1.9 years) and also from fecal DNA samples, for a total of 42 individuals analyzed for genetic diversity. The St. John deer data set averaged 4.19 alleles per marker and demonstrates the second lowest number of alleles (A) when compared to other populations of Odocoileus virginianus (4.19). Heterozygosity was similar to the other studies (0.54) with little evidence of inbreeding. To explain the level of heterozygosity and level of inbreeding within the St. John population, three hypotheses are proposed, including the effect of intrinsic biological traits within the population, a recent infusion of highly heterogeneous loci from North American populations, and a consistent level of immigration from a nearby island. Additional work is needed to further understand the genetic history of the St. John and regional deer populations.

Characterization of the genetic diversity of a population of Odocoileus virginianus veraecrucis in captivity using microsatellite markers

The genetic diversity and effective population size (Ne) of a population of Odocoileus virginianus veraecrucis in captivity were characterized in the Wildlife Management Unit “El Pochote”, located in Ixtaczoquitlán, Veracruz, Mexico. Blood tissue was collected from 20 individuals of the reproductive nucleus, its genomic DNA was extracted, and genetic diversity was characterized by six microsatellites amplified by PCR and visualized in polyacrylamide gels. With four polymorphic microsatellites, 66.7% of the population’s genetic variation was explained, which was characterized by an allelic diversity that fluctuated between 9 and 28 alleles (18 average alleles), suggesting a mean allelic diversity (Shannon index = 2.6 ± 0.25), but only 12 ± 2.9 effective alleles would be fixed in the next generation. The heterozygosity observed (Ho= 0.81) exceeded that expected (He= 0.79) and these were significantly different (P> 0.05), as a result of a low genetic structure in the population (fixation index F = -0.112 ± 0.03), due to the genetic heterogeneity that each sample contributed, since the specimens came from different geographical regions. The Ne was 625 individuals and a 1:25 male:female ratio, with which 100% of the genetic diversity observed can be maintained for 100 years. The information obtained in the study can help in the design of a reproductive management program to maintain the present genetic diversity, without risk of losses due to genetic drift and inbreeding.

Subspecific identity and a comparison of genetic diversity between wild and ex situ wildebeest

The original North American ex situ wildebeest population was believed to originate from the white-bearded wildebeest (Connochaetes taurinus albojubatus), which is both morphologically distinct and geographically separated from the brindled wildebeest (C. t. taurinus). However, after an import of wildebeest into North America in 2001, managers have suspected that white-bearded and brindled wildebeest were mixed in herds at multiple institutions. We sequenced the mitochondrial control region (d-loop) from a portion of the managed North American population and compared our sequences with previously published sequences from wild individuals to determine the subspecific identity and genetic diversity of our ex situ population. We were able to confidently identify C. t. albojubatus as the subspecies identity of the sampled portion of our population. Within our population, haplotype and nucleotide diversity were low (0.169 and 0.001, respectively) with a single common haplotype (H1) containing 41 of the 45 individuals sequenced, while two rare haplotypes (H2 and H3) were derived from three individuals and a single individual, respectively. Nucleotide and haplotype diversity were greater overall in the wild populations compared with our managed population. However, C. t. albojubatus was found to exhibit lower nucleotide diversity in both wild and ex situ populations when compared to other wild subspecies. Though the overall goal of the North American wildebeest population is for public education and not reintroduction, maintaining genetic diversity is vital for the long-term viability of this managed population, which may benefit from periodic supplementation of wild animals.

Estimating body mass of Florida white-tailed deer from standard age and morphometric measurements

Context Measuring a mammal’s body mass has importance in understanding nutritional condition, reproductive biology and ecology. It can be impractical for a researcher to measure the body mass when equipment needed to weigh individuals is inadequate or unavailable. Aims The purpose of this study was to develop a model to accurately estimate the body mass of hunter-harvested Florida white-tailed deer (Odocoileus virginianus osceola, Odocoileus virginianus seminolus) based on the relationship between scale mass, sex and standard age and morphometric measurement predictor variables easily obtainable in the field. Methods An information-theoretic approach was used to evaluate simple and multiple linear regression models with 67% of the data, and the best model in the set was validated using the remaining 33%. Key results Chest girth was the best single predictor of body mass. A global model including sex, age, age2 and body length variables was better supported than chest girth alone, and subspecies information did not contribute significantly to the body-mass–predictor-variable relationship. The best model explained 98.5% of the variation in body mass as follows: body mass (kg) = –18.41 + 6.53 × sex (0 = female, 1 = male) + 5.04 × age (year) – 0.49 × age2 (year2) + 4.76 × 10−3 × chest girth2 (cm2) + 0.12 × body length (cm). The 95% confidence interval on the bias of the estimated body mass of the best model was –0.50 to 0.59 kg. The difference between estimated and scale body mass was –0.04 kg ± 0.28 (s.e.). Conclusions Individuals maintained a similar proportion of body mass to predictor variables, and differences between the observed and estimated body mass of model applied to the validation dataset were not significant. Implications The validated body-mass-estimation model presented will enable accurate estimates of the body mass of white-tailed deer in cases where standard age and morphometric measurements are available, but the individuals were not weighed. These results provide a basis to formulate and parameterise body-mass-estimation models for other white-tailed deer subspecies and populations. Without the need for specialised equipment, the body-mass-estimation model can be used by personnel involved in white-tailed deer research, management and sport hunting to assess trends in individual and population health in support of this species’ conservation. Photograph by Carlton Ward Jr.

The complete mitochondrial genomes of nine white-tailed deer subspecies and their genomic differences

The white-tailed deer ( Odocoileus virginianus ) is an important, sustainable-use species in Mexico; 14 subspecies are widely distributed throughout the Mexican territory. The criteria for classifying subspecies is based on morphological features throughout their geographical range; however, the complete genetic characterization of Mexican subspecies has not been established. The objective of the present work is to report the mitogenomes of 9 of the 14 white-tailed deer subspecies from Mexico and identify their unique variations. Typical vertebrate mitogenomes structures (i.e., 13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes) were observed in the studied subspecies. The greatest numbers of polymorphisms were identified in the D-loop, ND4, ND5, CYTB/COI, ATP6, and COIII genes. Phylogenetic analyses showed that the southern and southeastern subspecies were distinct from the central and northern subspecies; the greatest genetic distances were also observed between these 2 groups. These subspecies-specific variations could be useful for designing a strategy to genetically characterize the studied subspecies.

El venado cola blanca es una de las especies de mayor importancia dentro del aprovechamiento de la fauna silvestre de México, donde se distribuyen de manera natural 14 subespecies. Actualmente, estas subespecies se han clasificado de acuerdo a sus variaciones fenotípicas que presentan a lo largo de su rango de distribución, sin embargo no se ha establecido la caracterización genética completa de las mismas. Es por esto que el objetivo del presente estudio es reportar los mitogenomas de 9 de las 14 subespecies de venado cola blanca, así como identificar las variaciones únicas de cada subespecie. En las 9 subespecies se observó la estructura típica de los mitogenomas de vertebrados (13 genes que codifican para proteínas, 22 ARNt, 2 ARNr). Los genes con mayor polimorfismo fueron D-loop, ND4, ND5, CYTB/COI, ATP6 y COIII. El análisis filogenético mostró la separación de las subespecies del sur y sureste de las subespecies del centro y norte del país, a su vez las distancias genéticas entre estos dos grupos fueron las más altas. Estas variaciones subespecie-específicas podrían ser útiles para diseñar una estrategia para caracterizar genéticamente las subespecies estudiadas.