Reproductive strategies in female Mountain and Dorcas gazelles (Gazella gazella gazella and Gazella dorcas)

Observations of reproduction in four gazelle populations in the semi–arid and arid habitats of Israel during three years have revealed intra– and interspecific differences. In the eastern Lower Galilee of northern Israel, female Mountain gazelles (Gazella gazella gazella) reproduce during every month of the year, conceive first at six months of age and exercise long parental care. Females of a population 80 km to the north (Upper Galilee) maintain a seasonal reproductive pattern, conceive first at 18 months of age and have a short parental care period. The latter pattern is similar to the Dorcas gazelle (Gazella dorcas) females of the southern Negev Desert. Interspecific similarities in reproduction of these two populations is attributed to the lack of free water during lactation in both environments where females rely on water available in plant tissue only. The importance of the daily accessibility to water during lactation in female gazelles is discussed. It is suggested that the timing of births and the ability of female gazelles to conceive while lactating are not species-specific characteristics but simply a matter of short-term adaptation to changing environmental conditions common understanding today that animal reproductive strategies are a function of prevailing environmental conditions.     

Latrine survey as a method to estimate the population size of Arabian gazelles (Gazella arabica)

Arabian gazelle (Gazella arabica) populations have been decimated in most parts of their original range. As a cryptic, crepuscular species, Arabian gazelles are difficult to observe, rendering monitoring programs for conservation purposes a challenging endeavour. Latrine mapping has been suggested as an effective, time- and cost-efficient tool to survey and estimate the abundance of gazelles in remote areas with low population densities. In the present study we collected data from five populations in Saudi Arabia to address the question of how population estimates can be inferred from such latrine counts and uncovered a non-linear relationship between both variables. Methodologies applied during the five surveys differed between study sites, so caution is required when interpreting our data. Still, given the immediate threat to the survival of the species, there is an urgent need to establish a time- and cost-efficient sampling method that will be vital for the conservation of remnant pockets of natural populations and for the proclamation of new protected areas in Saudi Arabia and other countries in the Middle East, and the present data are the only available source of information in this context.     

Growth stages and ageing criteria of Arabian Mountain gazelles (Gazella gazella Pallas, 1766: Antilopinae,Bovidae)

This research project was designed to be of both academic and practical value in the conservation of Mountain gazelle and represents an attempt to provide data for sex and age classification of this endangered species hitherto unpublished. Growth data and ageing criteria of 177 individuals of known age, obtained from a captive population, kept under uniform conditions at King Khalid Wildlife Research Centre in Saudi Arabia, were examined. Measurements of horn length, shoulder height, living body weight, neck circumference and forehead-horn length ratio were established and a field classification for ageing female and male Mountain gazelles was suggested.     

Post-mortem semen cryopreservation and characterization in two different endangered gazelle species (Gazella gazella and Gazella dorcas) and one subspecies (Gazella gazelle acaiae)

Both Gazella gazella and Gazella dorcas are endangered species with continually dwindling population size, yet basic knowledge on their spermatozoa is missing. Semen collected post-mortem (PM) from the cauda epididymis of five adult gazelles (three Gazella gazella gazella, one Gazella gazella acaiae and one G. dorcas) was cryopreserved using directional freezing of large volumes (8 mL) with egg-yolk-free extender. Sperm size measurements and SYBR-14/propodium iodide (PI) viability stain validation for use in gazelles were conducted. Post-thaw characterization included motility, viability, acrosome damage evaluation, computerized motility characterization and morphology and sperm motility index (SMI) was calculated. Extracted sperm motility was 71.67+/-11.67% (mean+/-S.E.M.). Post-thaw motility ranged between 15% and 63%, viability was 57.49+/-3.24%, intact acrosome was detected in 63.74+/-2.6% (median 64.8%, upper/lower quartiles 71.79%, 61.82%), and normal morphology ranged between 41% and 63%. Motility characterization showed two sub-groups-highly active and progressively motile spermatozoa with SMI of 62.75+/-0.38 and low activity and poorly progressive with SMI of 46.16+/-1.53. Our results indicate that PM preservation of gazelle spermatozoa with satisfactory post-thaw viability is possible and cryobanking is achievable.     

Sex difference in the communicatory significance of localized defecation sites in Arabian gazelles (Gazella arabica)

Mammalian scent marking in localized defecation sites (latrines) has often been interpreted in the context of (male) territory defense. However, latrines could have different functions in males and females, especially where territorial males monopolize groups of females with stable social alliances and pronounced home range overlap. We investigated the communicatory significance of latrines in wild Arabian gazelles (Gazella arabica) and assessed the spatial distribution of latrines within home ranges. Latrine density and utilization was highest in the center of female group home ranges, and less frequent in peripheral home range sections, pointing towards communication within groups rather than towards territoriality. When considering male home ranges, latrine densities and utilization were higher in non-overlap zones, contradicting a territorial function. This pattern appears to be caused by more females than territorial males per given area establishing latrines. A subsequent survey of latrine utilization, based on camera trapping, suggests that males use latrines for territory defense: males visited latrines in overlap zones disproportionally more often than females, and successions of two males prevailed. Our study thus highlights that male territorial marking can be masked when males and females use the same marking system for different purposes.     

Phylogenetic analyses of mitochondrial DNA suggest a sister group relationship between Xenarthra (Edentata) and Ferungulates

Phylogenetic analysis of 12 protein-coding genes from complete mitochondrial DNA (mtDNA) molecules of various mammals including a xenarthran representative, the armadillo (Dasypus novemcinctus), showed that the order Xenarthra (Edentata) is a sister group to the ferungulates (carnivores, perissodactyls, artiodactyls, cetaceans). Morphological and previous molecular analyses have placed the Xenarthra basal to other extant eutherians. The present findings are in striking contrast with that understanding. The results suggest that Xenarthra and ferungulates separated about 86 MYA.      

Phylogenetic and population genetic analyses of diploid Leucaena (Leguminosae; Mimosoideae) reveal cryptic species diversity and patterns of divergent allopatric speciation

? Premise of the study: Leucaena comprises 17 diploid species, five tetraploid species, and a complex series of hybrids whose evolutionary histories have been influenced by human seed translocation, cultivation, and subsequent spontaneous hybridization. Here we investigated patterns of evolutionary divergence among diploid Leucaena through comprehensively sampled multilocus phylogenetic and population genetic approaches to address species delimitation, interspecific relationships, hybridization, and the predominant mode of speciation among diploids. ? Methods: Parsimony- and maximum-likelihood-based phylogenetic approaches were applied to 59 accessions sequenced for six SCAR-based nuclear loci, nrDNA ITS, and four cpDNA regions. Population genetic comparisons included 1215 AFLP loci representing 42 populations and 424 individuals. ? Results: Phylogenetic results provided a well-resolved hypothesis of divergent species relationships, recovering previously recognized clades of diploids as well as newly resolved relationships. Phylogenetic and population genetic assessments identified two cryptic species that are consistent with geography and morphology. ? Conclusions: Findings from this study highlight the importance and utility of multilocus data in the recovery of complex evolutionary histories. The results are consistent with allopatric divergence representing the predominant mode of speciation among diploid Leucaena. These findings contrast with the potential hybrid origin of several tetraploid species and highlight the importance of human translocation of seed to the origin of these tetraploids. The recognition of one previously unrecognized species (L. cruziana) and the elevation of another taxon (L. collinsii subsp. zacapana) to specific status (L. zacapana) is consistent with a growing number of newly diagnosed species from neotropical seasonally dry forests, suggesting these communities harbor greater species diversity than previously recognized.     

Sperm cryopreservation in three species of endangered gazelles (Gazella cuvieri,G. dama mhorr,and G. dorcas neglecta)

Long-term storage of semen by cryopreservation, with high recovery rates on thawing, is essential for the establishment of genetic resource banks of endangered species. The purpose of the present study was to evaluate various diluents for the cryopreservation of spermatozoa from three species of gazelles (genus Gazella) in a captive breeding program. The diluents compared were Tes (N-tris(hydroxymethyl)methyl-2 aminoethane sulfonic acid)-Tris with 5% egg yolk and 6% glycerol (TEST) and Triladyl, yolk-citrate, Tris-trehalose, and Tris-lactose-all of them with 20% egg yolk and 6% (Triladyl) or 8% glycerol. Semen was obtained by electroejaculation from 12 G. cuvieri, 12 G. dama, and 13 G. dorcas males. Samples with less than 50% motile sperm, positive endosmosis, or acrosome integrity were not used. Diluted samples were loaded into 0.25-ml straws, cooled slowly to 5 degrees C over 1.5 h (-0.16 degrees C/min), equilibrated at that temperature for 2 h, frozen in nitrogen vapors for 10 min, and plunged into liquid nitrogen. Subsamples were assessed fresh, after refrigeration-equilibration, after freezing and thawing, and 2 h after thawing. Differences were seen between diluents, with best overall recovery rates after freezing and thawing found with Triladyl, TEST, and Tris-trehalose in G. cuvieri, TEST in G. dama, and Triladyl and TEST in G. dorcas. Differences were observed between species in the ability to withstand freezing and thawing, with best results seen in G. dorcas, intermediate results in G. dama, and worst results in G. cuvieri. These differences were inversely related to the average values of inbreeding of these populations. The underlying mechanism responsible for these differences may be a differential resistance to osmotic shock.     

Phylogenetic and population genetic analyses of Phaeosphaeria nodorum and its close relatives indicate cryptic species and an origin in the Fertile Crescent

The origin of the fungal wheat pathogen Phaeosphaeria nodorum remains unclear despite earlier intensive global population genetic and phylogeographical studies. We sequenced 1683 bp distributed across three loci in 355 globally distributed Phaeosphaeria isolates, including 74 collected in Iran near the center of origin of wheat. We identified nine phylogenetically distinct clades, including two previously unknown species tentatively named P1 and P2 collected in Iran. Coalescent analysis indicates that P1 and P2 are sister species of P. nodorum and the other Phaeosphaeria species identified in our analysis. Two species, P. nodorum and P. avenaria f. sp. tritici 1 (Pat1), comprised ～85% of the sampled isolates, making them the dominant wheat-infecting pathogens within the species complex. We designed a PCR-RFLP assay to distinguish P. nodorum from Pat1. Approximately 4% of P. nodorum and Pat1 isolates showed evidence of hybridization. Measures of private allelic richness at SSR and sequence loci suggest that the center of origin of P. nodorum coincides with its host in the Fertile Crescent. We hypothesize that the origin of this species complex is also in the Fertile Crescent, with four species out of nine found exclusively in the Iranian collections.     

Relatedness and other finescale population genetic analyses in the threatened eastern box turtle (Terrapene c. carolina) suggest unexpectedly high vagility with important conservation implications

Genetic analyses of populations are essential to the conservation of threatened and cryptic taxa such as Chelonians. Turtles and tortoises are among the most imperiled vertebrate taxa worldwide, yet many of the natural history traits remain unknown leaving management decisions ill- or improperly informed. The eastern box turtle Terrapene c. carolina is no exception, with many gaps in our knowledge about traits such as juvenile dispersal and patterns of relatedness across the landscape, especially as it is a species not particularly tied to water and vulnerable to human disturbance. In addition, all long-term studies of this species have documented demographic population declines, even in protected habitats. In this study we explore finescale population structuring, gene flow, dispersal, and relatedness at four sites across the species range. These sites vary in habitat fragmentation and surrounding habitat quality. Many radiotelemtery and mark-recapture studies suggest that Terrapene spp. have a sedentary natural history, with small and temporally conserved home ranges and little propensity for dispersal. Based on these data we predicted that populations would be highly structured at fine geographic scales, closely related individuals (1st- and 2nd-degree relatives) would coexist in close proximity, and individuals exhibiting transient behavior would be true transients. All sites had low levels of population structuring, mean pairwise relatedness values were statistically zero, over 90 % of pairs of individuals were unrelated, 4.4–8.7 % were half-siblings, and fewer than 1.0 % were full siblings or parent-offspring pairs. These patterns were consistent across all four sites, regardless of habitat fragmentation. Furthermore, while some related pairs were found within a few meters of each other, others ranged up to 33 km apart. We found that one of two individuals with transient behavior was indeed a true genetic transient. These findings suggest that box turtles may be much more vagile than current management practices recognize. As most turtle species are strongly affected by anthropogenic disturbance, many may require much larger contiguous blocks of intact habitat for species persistence as the box turtle likely does. Management plans may therefore need to be updated to allow for safe and effective long-distance dispersal at the appropriate spatial scales in order to maintain genetic health of these species.     

Low genetic diversity in the vulnerable Goitred Gazelle,Gazella subgutturosa (Cetartiodactyla: Bovidae), in Iran: potential genetic consequence of recent population declines

The Goitered Gazelle, Gazella subgutturosa, is the most widespread gazelle species in the Middle East and central Asia inhabiting desert and semi-desert habitats. Today it is threatened and its geographic range and population size have experienced significant decline in the last decades. In Iran, the remnant populations are confined to fragmented habitats. We aimed to characterise genetic diversity and phylogenetic status of the populations of Goitered Gazelle in Central Iran and to evaluate the potential effect of a historic population bottleneck on the genetic variation of today’s population. We used noninvasive sampling to uncover structure and level of genetic variation in a fragment of the cytochrome-b gene from 170 samples. Genealogical analyses were performed using HKY+I model and phylogenetic trees reconstructed using Bayesian inference and maximum likelihood. We found extremely low levels of genetic variation, with altogether only five haplotypes in samples from different populations. Overall haplotype diversity was 0.081 and nucleotide diversity 0.0003. The mean observed mismatch between any two sequences was 0.093 with the largest peak for small numbers. The mismatch distribution fit the model of population expansion and suggested that gazelles had experienced a sudden expansion. An unrooted median-joining network analysis of mtDNA haplotypes showed a star-like structure which few mutations steps separating the haplotypes from other regions. Our findings strengthen the urgency of preserving the species’ genetic diversity to prevent local extinction.     

Phylogenetic analyses suggest a hybrid origin of the figs (Moraceae: Ficus) that are endemic to the Ogasawara (Bonin) Islands, Japan

The Ogasawara Islands are oceanic islands and harbor a unique endemic flora. There are three fig species (Ficus boninsimae, F. nishimurae and F. iidaiana) endemic to the Ogasawara Islands, and these species have been considered to be closely related to Ficus erecta, and to have diverged within the islands. However, this hypothesis remains uncertain. To investigate this issue, we assessed the phylogenetic relationships of the Ogasawara figs and their close relatives occurring in Japan, Taiwan and South China based on six plastid genome regions, nuclear ITS region and two nuclear genes. The plastid genome-based tree indicated a close relationship between the Ogasawara figs and F. erecta, whereas some of the nuclear gene-based trees suggested this relationship was not so close. In addition, the phylogenetic analyses of the pollinating wasps associated with these fig species based on the nuclear 28S rRNA and mitochondrial cytB genes suggested that the fig-pollinating wasps of F. erecta are not sister to those of the Ogasawara figs These results suggest the occurrence of an early hybridization event(s) in the lineage leading to the Ogasawara figs.     

Comparison of population genetic diversity between a rare, narrowly distributed species and a common, widespread species of Alnus (Betulaceae)

Comparisons of population genetic diversity between related rare and widespread species provide valuable insights to the consequences of rarity and are critical for conservation planning. Population genetic diversity of A. maritima, a rare species, was compared with its common, widespread congener A. serrulata to evaluate the impacts of small population size and high isolation on genetic diversity in A. maritima and to provide population genetic data to be used in conservation planning for A. maritima. Genetic data were also used to evaluate whether the disjunct distribution of A. maritima was due to range reduction or anthropogenic dispersal. Genetic diversity was lower in A. maritima (H(e) = 0.217) than in A. serrulata (H(e) = 0.268), and there is also higher inbreeding within A. maritima populations (f = 0.483) than A. serrulata populations (f = 0.269). The partitioning of genetic variation was also higher among A. maritima populations (Θ = 0.278), but not significantly different from that of A. serrulata (Θ = 0.197). Significant genetic differences among A. maritima populations support using local populations as seed sources for regional conservation efforts. The results also indicate that the highly disjunct distribution of A. maritima is due to natural range reduction in the past and not anthropogenic establishment of Oklahoma and Georgia populations.     

Phylogenetic analyses of a combined data set suggest that the Attheya lineage is the closest living relative of the pennate diatoms (Bacillariophyceae)

A Bayesian analysis of a seven gene data set was conducted to reconstruct phylogenetic relationships among a sample of centric and pennate diatoms and to test alternative hypotheses about the closest living relative of Bacillariophyceae. A lineage, composed of two Attheya species, was inferred to share the most recent common ancestor with Bacillariophyceae--a relationship that was also corroborated by the combined parsimony analysis. All competing hypotheses about the closest living relative of Bacillariophyceae were rejected because 100% of the trees in the post-burn-in sample in the Bayesian analysis supported the Attheya-Bacillariophyceae clade. According to a partitioned Bremer support analysis, the majority of the genes in the combined data matrix supported the Attheya--Bacillariophyceae relationship. The global topology of the phylogenetic tree indicated that a monophyletic group consisting of Thalassiosirales and Toxarium undulatum formed the deepest branch followed by a node uniting a clade composed of Bacillariophyceae/Attheya species and a lineage made up of Eucampia zoodiacus, Chaetocerotales, Lithodesmiales, Triceratiales, Biddulphiales and Cymatosirales. Except for the phylogenetic positions of Lithodesmiales, Thalassiosira sp and Skeletonema costatum, the optimal tree obtained from the combined parsimony analysis showed the same branching order of taxa as those seen in the consensus tree inferred from three independent Markov chain Monte Carlo analyses. Noteworthy findings are that Toxarium undulatum shares a strongly supported node with Thalassiosirales and that the genus Attheya is not a member of the Chaetocerotales lineage.     

Multilocus genetic analyses differentiate between widespread and spatially restricted cryptic species in a model ascidian

Elucidating the factors that shape species distributions has long been a fundamental goal in ecology and evolutionary biology. In spite of significant theoretical advancements, empirical studies of range limits have lagged behind. Specifically, little is known about how the attributes that allow species to expand their ranges and become widespread vary across phylogenies. Here, we studied the ascidian Botryllus schlosseri, a worldwide invasive species that is also characterized by marked genetic subdivision. Our study includes phylogenetic and population genetic data based on mitochondrial and nuclear genes, as well as polymorphic microsatellites for B. schlosseri colonies sampled from the southern and northern coasts of Europe and the eastern and western coasts of North America. We demonstrate that this well-known model organism comprises three highly divergent and probably reproductively isolated cryptic species (A, D and E), with two more (B and C) being suggested by data retrieved from GenBank. Among these, species A, recovered in all of the surveyed regions, is by far the most common and widespread. By contrast, species B-E, occurring mostly in sites from northern Europe, are considerably more geographically restricted. These findings, along with inferences made on transport opportunity, suggest that divergent evolutionary histories promoted differences in invasive potential between B. schlosseri sibling species, indicating that attributes that facilitate dramatic shifts in range limits can evolve more easily and frequently than previously thought. We propose environmental disturbance as a selective force that could have shaped the evolution of invasiveness in the B. schlosseri complex.     

Noninvasive genetic analyses for estimating population size and genetic diversity of the remaining Far Eastern leopard (Panthera pardus orientalis) population

Understanding and monitoring the population status of endangered species is vital for developing appropriate management interventions. We used noninvasive genetic analyses to obtain ecological and genetic data on the last remaining Far Eastern leopard population in the world. During seven winters from 2000–2001 to 2007–2008, we collected feces, hair, and saliva from most of the leopard habitat. Of the 239 leopard samples collected during the study period, 155 were successfully genotyped at 13 microsatellite loci and 37 individuals (18 males and 19 females) were identified. Population size estimates based on the Capwire model were 28 (95 % CI 19–38) in 2002–03 and 26 (95 % CI 13–33) in 2007–2008. The leopard population had a low level of genetic diversity (expected and observed heterozygosity = 0.43; average number of alleles per locus = 2.62), and effective population size was estimated to be low (N _e = 7–16) by two genetic-based methods. We observed little improvement in the genetic diversity during the study period and did find an indication of allele loss compared with individuals from the mid-1990s, suggesting that the remaining population will continue to suffer loss of genetic diversity. Given the small population size and the low genetic diversity, with little expectation of replenishment of the genetic variation by natural immigration, successful expansion of available habitat and development of a second population based on captive individuals may be crucial for persistence of this leopard subspecies in the wild.     

Limited structure and widespread diversity suggest potential buffers to genetic erosion in a threatened grassland shrub Pimelea spinescens (Thymelaeaceae)

Pimelea spinescens is a critically endangered species of the temperate grasslands of southeastern Australia. Two subspecies are recognised. Subspecies, P. spinescens subsp. spinescens, formerly common and widespread, is found in isolated remnants of previously extensive grasslands. The second subspecies, subsp. pubiflora, is thought to have been historically rare with only two geographically-isolated extant populations. The grassland communities exist now as fragmented remnants representing <1 % of their extent prior to European settlement in the early 1800s. Conservation management strategies for species in these critically endangered ecosystems rely on an understanding of genetic diversity and population structure to ensure long-term evolutionary potential. We used chloroplast DNA (cpDNA) and microsatellite markers to examine the population genetic structure of both subspecies. Analysis of cpDNA revealed 14 haplotypes with high divergence between the single haplotype found in subsp. pubiflora and most remaining haplotypes restricted to subsp. spinescens. Microsatellites also indicated high genetic differentiation between subspecies but little evidence of sub-structuring within either subspecies. Results suggest that seed dispersal has not been as limited as previously thought. In this fragmented habitat, a lack of genetic structure suggests buffers to genetic erosion, with current patterns reflecting genetic diversity prior to fragmentation. Plant longevity and the presence of seed banks may contribute to the maintenance of these patterns, resulting in a lag between fragmentation and genetic erosion. Whilst factors such as longevity and seed banks may be preserving historic genetic diversity, management is required to ensure the maintenance of this diversity into the future.