Seasonal and age-related changes in the micro-anatomy of the prostate gland of the Subantarctic fur seal, Arctocephalus tropicalis

The prostate glands of male Subantarctic fur seals Arctocephalus tropicalis, taken at Gough Island (40°20'S, 09°54'W) between November 1977 and October 1978, were examined. Significant changes in the mass of the prostate, the diameter of the alveoli and height of the secretory epithelium precede the breeding season and support the fact that A. tropicalis is a seasonal breeder. Peak activity of the prostate is reached during November-January. We propose that seasonal changes in the prostate gland, and in male reproductive activity in general, may be cued by changing photoperiod. Micro-anatomical features of the prostate of the male Subantarctic fur seal differ between different age groups. Peak prostate mass, alveoli diameter and secretory cell height indicate that Subantarctic fur seal males reach full adulthood at 10–11 years of age

Oedipus complex in an Antarctic fur seal pup?

We present the first evidence of a possible case of the Oedipus complex in a nonprimate. An Antarctic fur seal pup, Arctocephalus gazella, unsuccessfully directed what appeared to be copulatory behaviour towards its own mother on several occasions. A herding sub-adult bull chased the pup from the female, which strengthens our suggestion that it was copulatory behaviour we witnessed. This seemed to constitute innocent sexual play with elements of the Oedipus complex rather than coercion because the female was not stressed nor did the pup possess the physical strength to coerce the female.The Department of Science and Technology, through the National Research Foundation (South Africa), provided financial support.http://www.springer.com/life+sci/zoology/journal/1016

Identification of naturally occurring hybrids between two overexploited sciaenid species along the South African coast

Hybridization between fish species can play a significant role in evolutionary processes and can influence management and conservation planning, however, this phenomenon has been widely understudied, especially in marine organisms. The distribution limits of two sciaenid species (silver kob, Argyrosomus inodorus, and dusky kob, A. japonicus) partly overlap along the South African coast, where both species have undergone severe depletion due to overfishing. Following the identification of a number of possible cases of species misidentification or hybridization (21 out of 422 individuals), nuclear and mitochondrial DNA data (12 microsatellite loci and 562 bp of the COI gene) were analysed to investigate the genetic composition of these individuals. Results indicated a field-based species misidentification rate of approximately 2.8% and a rate of natural hybridization of 0.7%. Interestingly, all hybrid fish resulted from first-generation (F1) hybridization events, which occurred exclusively between silver kob females and dusky kob males. Whether hybridization is the result of natural events (such as secondary contact following a shift in distribution range), or anthropogenic activities (size-selective pressure due to overfishing), these findings have important implications for critical recovery and future management of these species in the wild.DAFF (South Africa)http://www.elsevier.com/locate/ympevhb201

Population genetics of Southern Hemisphere tope shark (<i>Galeorhinus galeus</i>) : Intercontinental divergence and constrained gene flow at different geographical scales

The tope shark (Galeorhinus galeus Linnaeus, 1758) is a temperate, coastal hound shark found in the Atlantic and Indo-Pacific oceans. In this study, the population structure of Galeorhinus galeus was determined across the entire Southern Hemisphere, where the species is heavily targeted by commercial fisheries, as well as locally, along the South African coastline. Analysis was conducted on a total of 185 samples using 19 microsatellite markers and a 671 bp fragment of the NADH dehydrogenase subunit 2 (ND2) gene. Across the Southern Hemisphere, three geographically distinct clades were recovered, including one from South America (Argentina, Chile), one from Africa (all the South African collections) and an Australia-New Zealand clade. Nuclear data revealed significant population subdivisions (FST = 0.192 to 0.376, p<0.05) indicating limited gene flow for tope sharks across ocean basins. Marked population connectivity was however evident across the Indian Ocean based on Bayesian clustering analysis. More locally in South Africa, F-statistics and multivariate analysis supported moderate to high gene flow across the Atlantic/ Indian Ocean boundary (FST = 0.035 to 0.044, p<0.05), with exception of samples from Struisbaai and Port Elizabeth which differed significantly from the rest. Discriminant and Bayesian clustering analysis indicated admixture in all sampling populations, decreasing from west to east, corroborating possible restriction to gene flow across regional oceanographic barriers. Mitochondrial sequence data recovered seven haplotypes (h = 0.216, π = 0.001) for South Africa, with one major haplotype shared by 87% of the individuals and at least one private haplotype for each sampling location except Port Elizabeth. As with many other coastal shark species with cosmopolitan distribution, this study confirms the lack of both historical dispersal and inter-oceanic gene flow while also implicating contemporary factors such as oceanic currents and thermal fronts to drive local genetic structure of G. galeus on a smaller spatial scale.Facultad de Ciencias Naturales y Muse

Genetic and phenotypic consequences of early domestication in black soldier flies (Hermetia illucens)

CITATION: Rhode, C. et al. 2020. Genetic and phenotypic consequences of early domestication in black soldier flies (Hermetia illucens). Animal Genetics. 51:752-762. doi:10.1111/age.12961The original publication is available at https://onlinelibrary.wiley.com/journal/13652052The black soldier fly, Hermetia illucens, is an emerging biotechnological agent with its larvae being effective converters of organic waste into usable bio-products including protein and lipids. To date, most operations use unimproved commercial populations produced by mass rearing, without cognisance of specific breeding strategies. The genetic and phenotypic consequences of these commercial practices remain unknown and could have a significant impact on long-term population viability and productivity. The aim of this study was thus to assess the genetic and phenotypic changes during the early phases of colony establishment and domestication in the black soldier fly. An experimental colony was established from wild founder flies and a new microsatellite marker panel was developed to assess population genetic parameters along with the phenotypic characteristics of each generational cohort under captive breeding. The experimental colony was characterised by a small effective population size, subsequent loss of genetic diversity and rapid genetic and phenotypic differentiation between the generational cohorts. Ultimately, the population collapsed by the fifth generation, most likely owing to the adverse effect of inbreeding depression following the fixation of deleterious alleles. Species with r-selected life history characteristics (e.g. short life-span, high fecundity and low larval survival) are known to pose particular challenges for genetic management. The current study suggests that sufficient genetic and phenotypic variations exist in the wild population and that domestication and strain development could be achieved with careful population augmentation and selection during the early stages of colony establishment.https://onlinelibrary.wiley.com/doi/10.1111/age.12961Publishers versio

Identification strategy for unknown pollutants using high-resolution mass spectrometry: Androgen-disrupting compounds identified through effect-directed analysis

Effect-directed analysis has been applied to a river sediment sample of concern to identify the compounds responsible for the observed effects in an in vitro (anti-)androgenicity assay. For identification after non-target analysis performed on a high-resolution LTQ-Orbitrap, we developed a de novo identification strategy including physico-chemical parameters derived from the effect-directed analysis approach. With this identification strategy, we were able to handle the immense amount of data produced by non-target accurate mass analysis. The effect-directed analysis approach, together with the identification strategy, led to the successful identification of eight androgen-disrupting compounds belonging to very diverse compound classes: an oxygenated polyaromatic hydrocarbon, organophosphates, musks, and steroids. This is one of the first studies in the field of environmental analysis dealing with the difficult task of handling the large amount of data produced from non-target analysis. The combination of bioassay activity assessment, accurate mass measurement, and the identification and confirmation strategy is a promising approach for future identification of environmental key toxicants that are not included as priority pollutants in monitoring programs

Transcriptome characterization of the South African abalone Haliotis midae using sequencing-by-synthesis

<p>Abstract</p> <p>Background</p> <p>Worldwide, the genus <it>Haliotis </it>is represented by 56 extant species and several of these are commercially cultured. Among the six abalone species found in South Africa, <it>Haliotis midae </it>is the only aquacultured species. Despite its economic importance, genomic sequence resources for <it>H. midae</it>, and for abalone in general, are still scarce. Next generation sequencing technologies provide a fast and efficient tool to generate large sequence collections that can be used to characterize the transcriptome and identify expressed genes associated with economically important traits like growth and disease resistance.</p> <p>Results</p> <p>More than 25 million short reads generated by the Illumina Genome Analyzer were <it>de novo </it>assembled in 22,761 contigs with an average size of 260 bp. With a stringent <it>E</it>-value threshold of 10^-10, 3,841 contigs (16.8%) had a BLAST homologous match against the Genbank non-redundant (NR) protein database. Most of these sequences were annotated using the gene ontology (GO) and eukaryotic orthologous groups of proteins (KOG) databases and assigned to various functional categories. According to annotation results, many gene families involved in immune response were identified. Thousands of simple sequence repeats (SSR) and single nucleotide polymorphisms (SNP) were detected. Setting stringent parameters to ensure a high probability of amplification, 420 primer pairs in 181 contigs containing SSR loci were designed.</p> <p>Conclusion</p> <p>This data represents the most comprehensive genomic resource for the South African abalone <it>H. midae </it>to date. The amount of assembled sequences demonstrated the utility of the Illumina sequencing technology in the transcriptome characterization of a non-model species. It allowed the development of several markers and the identification of promising candidate genes for future studies on population and functional genomics in <it>H. midae </it>and in other abalone species.</p

Effect of sitagliptin on cardiovascular outcomes in type 2 diabetes

BACKGROUND: Data are lacking on the long-term effect on cardiovascular events of adding sitagliptin, a dipeptidyl peptidase 4 inhibitor, to usual care in patients with type 2 diabetes and cardiovascular disease. METHODS: In this randomized, double-blind study, we assigned 14,671 patients to add either sitagliptin or placebo to their existing therapy. Open-label use of antihyperglycemic therapy was encouraged as required, aimed at reaching individually appropriate glycemic targets in all patients. To determine whether sitagliptin was noninferior to placebo, we used a relative risk of 1.3 as the marginal upper boundary. The primary cardiovascular outcome was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina. RESULTS: During a median follow-up of 3.0 years, there was a small difference in glycated hemoglobin levels (least-squares mean difference for sitagliptin vs. placebo, -0.29 percentage points; 95% confidence interval [CI], -0.32 to -0.27). Overall, the primary outcome occurred in 839 patients in the sitagliptin group (11.4%; 4.06 per 100 person-years) and 851 patients in the placebo group (11.6%; 4.17 per 100 person-years). Sitagliptin was noninferior to placebo for the primary composite cardiovascular outcome (hazard ratio, 0.98; 95% CI, 0.88 to 1.09; P<0.001). Rates of hospitalization for heart failure did not differ between the two groups (hazard ratio, 1.00; 95% CI, 0.83 to 1.20; P = 0.98). There were no significant between-group differences in rates of acute pancreatitis (P = 0.07) or pancreatic cancer (P = 0.32). CONCLUSIONS: Among patients with type 2 diabetes and established cardiovascular disease, adding sitagliptin to usual care did not appear to increase the risk of major adverse cardiovascular events, hospitalization for heart failure, or other adverse events