Diversity of mitochondrial DNA in 3 species of great whales before and after modern whaling.

The 20th century commercial whaling industry severely reduced populations of great whales throughout the Southern Hemisphere. The effect of this exploitation on genetic diversity and population structure remains largely undescribed. Here, we compare pre- and post-whaling diversity of mitochondrial DNA (mtDNA) control region sequences for 3 great whales in the South Atlantic, such as the blue, humpback, and fin whale. Pre-whaling diversity is described from mtDNA extracted from bones collected near abandoned whaling stations, primarily from the South Atlantic island of South Georgia. These bones are known to represent the first stage of 20th century whaling and thus pre-whaling diversity of these populations. Post-whaling diversity is described from previously published studies reporting large-scale sampling of living whales in the Southern Hemisphere. Despite relatively high levels of surviving genetic diversity in the post-whaling populations, we found evidence of a probable loss of mtDNA lineages in all 3 species. This is evidenced by the detection of a large number of haplotypes found in the pre-whaling samples that are not present in the post-whaling samples. A rarefaction analysis further supports a loss of haplotypes in the South Atlantic humpback and Antarctic blue whale populations. The bones from former whaling stations in the South Atlantic represent a remarkable molecular archive for further investigation of the decline and ongoing recovery in the great whales of the Southern Hemisphere.

Taxonomic status of otter species in Nakai-Nam Theun National Park, Lao PDR, based on DNA evidence.

Otter populations are threatened by habitat loss, pollution, conflicts with humans, and illegal wildlife trade to meet the demand for pets, for their fur, and for parts used in traditional medicines. Baseline information on the distribution, population genetic diversity, and connectivity is crucial to inform conservation management decisions; however, reliable data from otter populations in Southeast Asia remain scarce. In this study, we conducted baseline otter fecal DNA surveys based on mitochondrial DNA (mtDNA) to identify species, assess the occurrence, and map the spatial distribution of genetic diversity and evolutionary relationships of otter populations using 1700 bp Cytochrome B - Control Region and mitogenome from Nakai-Nam Theun National Park in the Annamite Mountains of Lao PDR. Of the total 56 samples identified to species, the majority (87.5%) was of the widely distributed Eurasian otter with three haplotypes (Lutra lutra; LLLA01-LLLA03), with a calculated haplotype diversity of 0.600 and a nucleotide diversity of 0.00141 based on mitogenome. The second species was the Asian small-clawed otter with only one haplotype detected (Aonyx cinereus; ACLA01). All Eurasian otter haplotypes were newly characterized and clustered within the strongly supported South-Southeast-North Asian clade of Lutra lutra. Compared with the European clade, the high mtDNA diversity of Lutra lutra in Nakai-Nam Theun National Park potentially reflects long-term demographic stability and lesser degree of population bottleneck during the last glacial maxima (LGM, ~21,000 years ago). The single haplotype detected in Asian small-clawed otters had not been detected in previous genetic studies. Our research is the first otter-specific noninvasive genetic study in Lao PDR and provides baseline insights into the otter population diversity in a regional priority site for biodiversity conservation.

Circum-Saharan Prehistory through the Lens of mtDNA Diversity.

African history has been significantly influenced by the Sahara, which has represented a barrier for migrations of all living beings, including humans. Major exceptions were the gene flow events that took place between North African and sub-Saharan populations during the so-called African Humid Periods, especially in the Early Holocene (11.5 to 5.5 thousand years ago), and more recently in connection with trans-Saharan commercial routes. In this study, we describe mitochondrial DNA (mtDNA) diversity of human populations from both sides of the Sahara Desert, i.e., both from North Africa and the Sahel/Savannah belt. The final dataset of 7213 mtDNA sequences from 134 African populations encompasses 470 newly collected and 6743 previously published samples, which were analyzed using descriptive methods and Bayesian statistics. We completely sequenced 26 mtDNAs from sub-Saharan samples belonging to the Eurasian haplogroup N1. Analyses of these N1 mitogenomes revealed their possible routes to the Sahel, mostly via Bab el-Mandab. Our results indicate that maternal gene flow must have been important in this circum-Saharan space, not only within North Africa and the Sahel/Savannah belt but also between these two regions.

The maternal perspective for five Slovenian regions: The importance of regional sampling.

BACKGROUND: The Slovenian territory is geographically positioned between the Alps, Adriatic Sea, Pannonian basin and the Dinaric Mountains and, as such, has served as a passageway for various populations in different periods of time. Turbulent historic events and diverse geography of the region have produced a diverse contemporary population whose genetic analysis could provide insight into past demographic events. AIM: The aims of this study were to characterize the Slovenian mitochondrial gene pool at the micro-geographic level and to compare it with surrounding populations. SUBJECTS AND METHODS: A total of 402 individuals from five Slovenian regions were analysed in this study by typing HVR I, HVR II and coding region polymorphisms of mtDNA. RESULTS: Analysis revealed 47 haplogroups and sub-haplogroups, the most common of which were H*, H1, J1c, T2 and U5a. Intra-population comparisons revealed a sharp gradient of the J1c haplogroup between Slovenian regions, with a peak frequency of 24.5% being observed in the population of the Littoral Region. CONCLUSION: The sharp gradient of the J1c haplogroup between Slovenian regions is in line with the archaeological horizon known as Impressed Ware culture and could, therefore, represent a genetic trace of the early Neolithic expansion route along the East Adriatic coastal region.

Reproductive biology and genetic diversity of the green turtle (Chelonia mydas) in Vamizi island, Mozambique.

INTRODUCTION: Vamizi, an Island located in the Western Indian Ocean, is visited by a small and not fully characterized green turtle (Chelonia mydas (L.)) population. This population is threatened by natural hazards and several human activities, which are used to identify conservation priorities for marine turtles. It was our aim to contribute to the knowledge of marine turtles that nest in Vamizi, with respect to its regional management, and to an area that may possibly be included on the UNESCO World Heritage List due to its potential Outstanding Universal Value. CASE DESCRIPTION: Here, we evaluate the nesting parameters (incubation period, clutch size, hatching and emergence successes rates) and patterns over an 8-year (2003 - 2010) conservation program. We also present the results of genetic diversity based on the analysis of approximately an 850 pb fragment of the mitochondrial DNA control region. DISCUSSION AND EVALUATION: We found that Vamizi beaches host a small number of nesting females, approximately 52 per year, but these have shown a reduction in their length. High hatching success (88.5 ± SD 17.2%, N = 649), emergence success rates (84.5 ± SD 20.4%, N = 649) were observed, and genetic diversity (N = 135), with 11 haplotypes found (7 new). It was also observed, in the later years of this study, a reduction in the incubation period, a dislocation of the nesting peak activity and an increase in the number of flooded nests and an increase of the number of nests in areas with lower human activity. CONCLUSIONS: Some resilience and behavioral plasticity seems to occur regarding human territory occupancy and climate changes. However, regardless of the results, aspects like what seems to be the reduction of some cohorts, the number of flooded nests and the diminishing of the incubation period (East and South facing beaches), show that conservation efforts have to be improved.