Search results for " genetics"

Drosophila Evolution over Space and Time (DEST) - A New Population Genomics Resource

2021

Abstract Drosophila melanogaster is a leading model in population genetics and genomics, and a growing number of whole-genome datasets from natural populations of this species have been published over the last 20 years. A major challenge is the integration of these disparate datasets, often generated using different sequencing technologies and bioinformatic pipelines, which hampers our ability to address questions about the evolution and population structure of this species. Here we address these issues by developing a bioinformatics pipeline that maps pooled sequencing (Pool-Seq) reads from D. melanogaster to a hologenome consisting of fly and symbiont genomes and estimates allele frequenc…

2018

Aposematic theory has historically predicted that predators should select for warning signals to converge on a single form, as a result of frequency-dependent learning. However, widespread variation in warning signals is observed across closely related species, populations and, most problematically for evolutionary biologists, among individuals in the same population. Recent research has yielded an increased awareness of this diversity, challenging the paradigm of signal monomorphy in aposematic animals. Here we provide a comprehensive synthesis of these disparate lines of investigation, identifying within them three broad classes of explanation for variation in aposematic warning signals: …

Evolution of the Globin Gene Family in Deuterostomes: Lineage-Specific Patterns of Diversification and Attrition

2012

In the Metazoa, globin proteins display an underlying unity in tertiary structure that belies an extraordinary diversity in primary structures, biochemical properties, and physiological functions. Phylogenetic reconstructions can reveal which of these functions represent novel, lineage-specific innovations, and which represent ancestral functions that are shared with homologous globin proteins in other eukaryotes and even prokaryotes. To date, our understanding of globin diversity in deuterostomes has been hindered by a dearth of genomic sequence data from the Ambulacraria (echinoderms + hemichordates), the sister group of chordates, and the phylum Xenacoelomorpha, which includes xenoturbel…

Comparative transcriptomic analysis of the mechanisms underpinning ageing and fecundity in social insects.

2021

The exceptional longevity of social insect queens despite their lifelong high fecundity remains poorly understood in ageing biology. To gain insights into the mechanisms that might underlie ageing in social insects, we compared gene expression patterns between young and old castes (both queens and workers) across different lineages of social insects (two termite, two bee and two ant species). After global analyses, we paid particular attention to genes of the insulin/insulin-like growth factor 1 signalling (IIS)/target of rapamycin (TOR)/juvenile hormone (JH) network, which is well known to regulate lifespan and the trade-off between reproduction and somatic maintenance in solitary insects…

Différenciation morphologique et génétique des populations de douroucoulis (Aotus infulatus, Primates, Platyrhiniens, Cebidae) provenant des rives dr…

2007

11 pages; La morphologie crânienne de 28 spécimens de douroucoulis (genre Aotus), provenant du Bassin amazonien, a été étudiée à l'aide de méthodes de morphométrie géométrique en trois dimensions. De nouveaux résultats concernant la distinction morphologique de populations de l'espèce Aotus infulatus, réparties de part et d'autre du rio Tocantins, sont proposés. Ces résultats morphologiques concordent avec la distinction génétique de ces populations publiée par Schneider – et Sampaio –, et indiquent probablement de récents et rapides changements évolutifs au sein de cette espèce. Les résultats de cette étude ont une application taxinomique, mais pourraient également ouvrir de nouvelles pers…

Climatic influence on the growth pattern ofPanthasaurus maleriensisfrom the Late Triassic of India deduced from paleohistology

2020

Metoposaurids are representatives of the extinct amphibian clade Temnospondyli, found on almost every continent exclusively in the Late Triassic deposits. Osteohistologically, it is one of the best-known temnospondyl groups, analyzed with a wide spectrum of methods, such as morphology, morphometry, bone histology or computed modelling. The least known member of Metoposauridae isPanthasaurus maleriensisfrom the Pranhita-Godavari basin in Central India, being geographically the most southern record of this family. For the first time the bone histology of this taxon was studied with a focus on the intraspecific variability of the histological framework and the relationship between the observed…

Ornamentation of dermal bones of Metoposaurus krasiejowensis and its ecological implications

2018

Background Amphibians are animals strongly dependent on environmental conditions, like temperature, water accessibility, and the trophic state of the reservoirs. Thus, they can be used in modern palaeoenvironmental analysis, reflecting ecological condition of the biotope. Methods To analyse the observed diversity in the temnospondyl Metoposaurus krasiejowensis from Late Triassic deposits in Krasiejów (Opole Voivodeship, Poland), the characteristics of the ornamentation (such as grooves, ridges, tubercules) of 25 clavicles and 13 skulls were observed on macro- and microscales, including the use of a scanning electron microscope for high magnification. The different ornamentation patterns fo…

Merging cranial histology and 3D-computational biomechanics : A review of the feeding ecology of a Late Triassic temnospondyl amphibian

2021

Finite Element Analysis (FEA) is a useful method for understanding form and function. However, modelling of fossil taxa invariably involves assumptions as a result of preservation-induced loss of information in the fossil record. To test the validity of predictions from FEA, given such assumptions, these results could be compared to independent lines of evidence for cranial mechanics. In the present study a new concept of using bone microstructure to predict stress distribution in the skull during feeding is put forward and a correlation between bone microstructure and results of computational biomechanics (FEA) is carried out. The bony framework is a product of biological optimisation; bon…

Visible implant elastomer (VIE) success in early larval stages of a tropical amphibian species

2020

AbstractAnimals are often difficult to distinguish at an individual level, but being able to identify individuals can be crucial in ecological or behavioral studies. In response to this challenge, biologists have developed a range of marking (tattoos, brands, toe-clips) and tagging (PIT, VIA, VIE) methods to identify individuals and cohorts. Animals with complex life cycles are notoriously hard to mark because of the distortion or loss of the tag across metamorphosis. In frogs, few studies have attempted larval tagging and none have been conducted on a tropical species. Here, we present the first successful account of VIE tagging in early larval stages (Gosner stage 25) of the dyeing poison…

Development of a low-alcoholic fermented beverage employing cashew apple juice and non-conventional yeasts

2019

Cashew apples are by-products in the production of cashew nuts, which are mostly left to rot in the fields. Cashew apple juice (CAJ), a highly nutritious beverage, can be produced from them. It is rich in sugars and ascorbic acid, but its high polyphenol content makes it bitter and astringent, and therefore difficult to commercialize. The kingdom of fungi contains more than 2000 yeast species, of which only a few species have been studied in relation to their potential to produce aroma compounds. The aim of this research was to develop a new low-alcoholic fermented beverage to valorize cashew apples. For this purpose, a screening was carried out employing non-conventional yeast species and …