Ecological and anthropogenic effects on the genomic diversity of lemurs in Madagascar.

Ecological variation and anthropogenic landscape modification have had key roles in the diversification and extinction of mammals in Madagascar. Lemurs represent a radiation with more than 100 species, constituting roughly one-fifth of the primate order. Almost all species of lemurs are threatened with extinction, but little is known about their genetic diversity and demographic history.

A global catalog of whole-genome diversity from 233 primate species.

The rich diversity of morphology and behavior displayed across primate species provides an informative context in which to study the impact of genomic diversity on fundamental biological processes. Analysis of that diversity provides insight into long-standing questions in evolutionary and conservation biology and is urgent given severe threats these species are facing. Here, we present high-coverage whole-genome data from 233 primate species representing 86% of genera and all 16 families.

The landscape of tolerated genetic variation in humans and primates.

Personalized genome sequencing has revealed millions of genetic differences between individuals, but our understanding of their clinical relevance remains largely incomplete. To systematically decipher the effects of human genetic variants, we obtained whole-genome sequencing data for 809 individuals from 233 primate species and identified 4.3 million common protein-altering variants with orthologs in humans.

The landscape of tolerated genetic variation in humans and primates.

Unlabelled: Personalized genome sequencing has revealed millions of genetic differences between individuals, but our understanding of their clinical relevance remains largely incomplete. To systematically decipher the effects of human genetic variants, we obtained whole genome sequencing data for 809 individuals from 233 primate species, and identified 4.3 million common protein-altering variants with orthologs in human.

Variation in predicted COVID-19 risk among lemurs and lorises.

The novel coronavirus SARS-CoV-2, which in humans leads to the disease COVID-19, has caused global disruption and more than 2 million fatalities since it first emerged in late 2019. As we write, infection rates are at their highest point globally and are rising extremely rapidly in some areas due to more infectious variants. The primary target of SARS-CoV-2 is the cellular receptor angiotensin-converting enzyme-2 (ACE2).

New density estimates of a threatened sifaka species (Propithecus coquereli) in Ankarafantsika National Park.

Propithecus coquereli is one of the last sifaka species for which no reliable and extensive density estimates are yet available. Despite its endangered conservation status [IUCN, 2012] and recognition as a flagship species of the northwestern dry forests of Madagascar, its population in its last main refugium, the Ankarafantsika National Park (ANP), is still poorly known. Using line transect distance sampling surveys we estimated population density and abundance in the ANP.

A DNA metabarcoding study of a primate dietary diversity and plasticity across its entire fragmented range.

In tropical regions, most primary ecosystems have been replaced by mosaic landscapes in which species must cope with a large shift in the distribution of their habitat and associated food resources. Primates are particularly vulnerable to habitat modifications. Most species persist in small fragments surrounded by complex human-mediated matrices whose structure and connectivity may strongly influence their dispersal and feeding behavior.

Density estimates of two endangered nocturnal lemur species from northern Madagascar: new results and a comparison of commonly used methods.

Very little information is known of the recently described Microcebus tavaratra and Lepilemur milanoii in the Daraina region, a restricted area in far northern Madagascar. Since their forest habitat is highly fragmented and expected to undergo significant changes in the future, rapid surveys are essential to determine conservation priorities. Using both distance sampling and capture-recapture methods, we estimated population densities in two forest fragments.

Landscape genetics of an endangered lemur (Propithecus tattersalli) within its entire fragmented range.

Habitat fragmentation may strongly reduce individuals' dispersal among resource patches and hence influence population distribution and persistence. We studied the impact of landscape heterogeneity on the dispersal of the golden-crowned sifaka (Propithecus tattersalli), an endangered social lemur species living in a restricted and highly fragmented landscape. We combined spatial analysis and population genetics methods to describe population units and identify the environmental factors which best predict the rates and patterns of genetic differentiation within and between populations.

Spatial variation in density and total size estimates in fragmented primate populations: the golden-crowned sifaka (Propithecus tattersalli).

The golden-crowned sifaka (Propithecus tattersalli) is an endangered lemur species found only in the Daraina region, a very restricted area in north-eastern Madagascar. Its forest habitat is highly fragmented and expected to suffer from significant changes in the near future. The species is poorly known and only one census study, carried out in 2000, has ever been published.

Molecular phylogeny and taxonomic revision of the sportive lemurs (Lepilemur, Primates).

Background: The number of species within the Malagasy genus Lepilemur and their phylogenetic relationships is disputed and controversial. In order to establish their evolutionary relationships, a comparative cytogenetic and molecular study was performed. We sequenced the complete mitochondrial cytochrome b gene (1140 bp) from 68 individuals representing all eight sportive lemur species and most major populations, and compared the results with those obtained from cytogenetic studies derived from 99 specimens.

Phylogenetic history of the Sifakas ( Propithecus: Lemuriformes) derived from cytogenetic studies.

The R-banded karyotypes of the different subspecies of Propithecus diadema and P. verreauxi are compared to each other and to that of P. tattersalli, as well as those previously reported of Indri indri and Avahi laniger.

Chromosomal evolution of the Hapalemur griseus subspecies (Malagasy Prosimian), including a new chromosomal polymorphic cytotype.

A cytogenetic study has been performed on Hapalemur griseus caught in different locations of the eastern and northern forests of Madagascar. This allowed the determination of the more precise distribution areas of the different subspecies and the isolation of a new cytogenetic polymorphic subspecies of H. griseus.

Genetic comparison between different populations of Eulemur macaco flavifrons in northwest Madagascar using RAPD markers.

Eulemur macaco flavifrons, the Sclater's black lemur, is a critically endangered subspecies of northwest Madagascar, which is not yet protected by any reserve. In order to study the feasibility of creating such a reserve, an area of outstanding biological importance was selected in the region of Maromandia-Sahamalaza, which is probably the only remaining place which would permit the long-term survival of the Sclater's black lemur. To determine if genetic management is needed for the Sahamalaza black lemur population, its genetic variability was estimated with random amplified polymorphic DNA (RAPD) markers and compared with other populations.

Comparison of genetic variability in wild insular and mainland populations of Eulemur macaco: implications for conservation strategy.

DNA fingerprinting analysis was used to investigate genetic variability within and between three wild populations of Eulemur macaco living on two islands and on the mainland. The analyses revealed that the genetic variability of the population from the smaller island was, as expected, lower than that from the larger island. Surprisingly, on the larger island the genetic variability was greater than on the mainland.

Chromosomal evolution in Malagasy lemurs: XII. Chromosomal banding study of Avahi laniger occidentalis (Syn: Lichanotus laniger occidentalis) and cytogenetic data in favour of its classification in a species apart-Avahi occidentalis.

A cytogenetical study of the western form of Avahi (Avahi laniger occidentalis) shows that its karyotype differs from that of A. laniger laniger by at least 3 chromosomal rearrangements. Meiotic chromosomal pairing of hypothetical hybrids has been constructed.