Environmental influences on the gametic investment of yellow dung fly males

The energetic investment per spermatozoon and in spermatogenesis is central to a male's reproductive strategy. Relatively little, however, is known about environmental influences on variation in male allocation decisions and associated trade-offs. Plasticity in sperm length and testis size in response to variable food and temperature conditions either before or after adult eclosion was investigated in Scathophaga stercoraria, a classic model organism for sperm competition. Both measures showed interesting and clear environmental effects and also a heritable component. Testis length, and thus presumably sperm production, showed a hypoallometric (b < 1), but non-linear increase with body size, indicating that the allometric relationship changed with size. Like body size, testis length decreased with increasing developmental temperatures, but also showed a complex cubic relationship with adult temperatures. In contrast, sperm length increased or showed a negative quadratic relationship with increasing temperatures. The increase of within-male variation in sperm length with increasing developmental temperature and decreasing adult food indicates that some of our treatments were stressful. Nevertheless, there was no evidence of a trade-off between testis size and sperm length. The missing effect of adult or larval food availability on testis and sperm length, despite strong effects of larval food on body size, suggests that investment into reproduction is less sensitive to food restriction than investment into growt

Deciphering the evolutionary history of the black soldier fly, Hermetia illucens, on a global scale

Insects are considered promising candidates for improving agronomic sustainability. Contrary to conventional livestock, however, genetic resources of farmed insects remain poorly characterized. We genotyped almost 3,000 black soldier fly (BSF) specimens from 150 wild and captive populations collected in 57 countries worldwide with newly developed microsatellite markers, providing individual genetic fingerprints throughout. Substantial global population genetic structure was detected by various complementary approaches such as analyses of molecular variance, pairwise population differentiation, isolation by distance, cluster analyses, and coalescence-based modelling, which further revealed complex sub-structuring shaped by naturally derived geographic distribution and human-mediated breed formation. In-depth reconstruction of the evolutionary history of the BSF using our novel highly resolving molecular tool kit infers ancient indigenous range expansions emanating from genetic hotspots within the Americas, and further dynamic demographic trajectories to all other non-native continents in recent history, resulting in pronounced diversification of genetically unique wild lineages via colonization from single-sources or intra specific admixture events. Conversely, globally predominant captive populations show reduced genetic diversity and, despite featuring distinct breeding-mediated footprints, trace back to a single origin that exhibits marked signatures of domestication. Fuelled by common mass-rearing operations, presently ongoing introgression between commercialized domesticated strains and wild populations was found to threaten the genetic integrity of local populations in some regions. Our comprehensive worldwide population genetic inventory of the BSF provides a benchmark for necessary investigation of this fly’s evolutionary ecology, and particularly allows fast and reliable genetic characterization in applied BSF research, with implications on harnessing the potential of this insect for solving urgent socio-economic challenges

Ivermectin sensitivity is an ancient trait affecting all ecdysozoa but shows phylogenetic clustering among sepsid flies

10.1111/eva.12152Evolutionary Applications75548-55

The Drosophila septate junctions beyond barrier function: Review of the literature, prediction of human orthologs of the SJ-related proteins and identification of protein domain families

The involvement of Septate Junctions (SJs) in critical cellular functions that extend beyond their role as diffusion barriers in the epithelia and the nervous system has made the fruit fly an ideal model for the study of human diseases associated with impaired Tight Junction (TJ) function. In this study, we summarized current knowledge of the Drosophila melanogaster SJ-related proteins, focusing on their unconventional functions. Additionally, we sought to identify human orthologs of the corresponding genes as well as protein domain families. The systematic literature search was performed in PubMed and Scopus databases using relevant key terms. Orthologs were predicted using the DIOPT tool and aligned protein regions were determined from the Pfam database. 3-D models of the smooth SJ proteins were built on the Phyre2 and DMPFold protein structure prediction servers. A total of 30 proteins were identified as relatives to the SJ cellular structure. Key roles of these proteins, mainly in the regulation of morphogenetic events and cellular signalling, were highlighted. The investigation of protein domain families revealed that the SJ-related proteins contain conserved domains that are required not only for cell-cell interactions and cell polarity but also for cellular signalling and immunity. DIOPT analysis of orthologs identified novel human genes as putative functional homologs of the fruit fly SJ genes. A gap in our knowledge was identified regarding the domains that occur in the proteins encoded by eight SJ-associated genes. Future investigation of these domains is needed to provide functional information. © 2020 Scandinavian Physiological Society. Published by John Wiley & Sons Lt