Local adaptation and colonization are potential factors affecting sexual competitiveness and mating choice in Anopheles coluzzii populations

The mating behaviour of the malaria vector Anopheles gambiae complex is an important aspect of its reproduction biology. The success of mosquito release programmes based on genetic control of malaria crucially depends on competitive mating between both laboratory-reared and wild individuals, and populations from different localities. It is known that intrinsic and extrinsic factors can influence the mating success. This study addressed some of the knowledge gaps about factors influcencing mosquito mating success. In semi-field conditions, the study compared the mating success of three laboratory-reared and wild allopatric An. coluzzii populations originating from ecologically different locations in Burkina Faso. Overall, it was found that colonization reduced the mating competitiveness of both males and females compared to that of wild type individuals. More importly, females were more likely to mate with males of their own population of origin, be it wild or colonised, suggesting that local adaptation affected mate choice. The observations of mating behaviour of colonized and local wild populations revealed that subtle differences in behaviour lead to significant levels of population-specific mating. This is the first study to highlight the importance of local adaptation in the mating success, thereby highlighting the importance of using local strains for mass-rearing and release of An. coluzzii in vector control programmes.

Breeding phenology of Common Redstart (Phoenicurus phoenicurus) and its reproduction biology with artificial nests in Northeastern Ukraine

The paper describes investigations on the reproduction biology (nesting, clutching, hatching, fledglings` departure) of the Common Redstart (Phoenicurus phoenicurus) in artificial nest boxes (AN) in Northeastern Ukraine. There were three sites of research: Hetman NNP, NPP “Gomilshansky Forests”, and RLP “Feldman Ecopark”. The research was performed during the nesting period from the first week of April to the first week of July in 2015‒2020. Annually, 5‒8 bird counts were conducted at each site. The first complete egg clutches at Hetman NNP were observed from 08.05 to 17.05 (2015‒2020) and at NPP “Gomilshansky Forests” from 02.05 to28.05 (2017‒2020). Dates of the first egg laying, at various conditions, had inter-annual variability because of unstable weather conditions in May. The average parameters of nests in AN at Hetman NNP were the following: diameter of nests (D) ‒ 124.1±6.3 mm; diameter of trays (d) ‒ 61.5±1.7 mm; nest height (H) ‒ 63.5±9.4 mm; depth of trays (h) ‒ 48.6±2.7 mm; nest mass (m) ‒ 43.7±3.8 mm. The size of complete clutches in Northeastern Ukraine was calculated when eggs were incubated. According to the average indicators, during 2015‒2020, the average size of the clutch was 6.9±0.3 (5‒8) eggs at Hetman NNP, 6.2±0.4 (6‒8) eggs at NPP “Gomilshansky Forests” and 8.5±0.5 (8‒9) eggs at RLP “Feldman Ecopark”. Incubation period of Ph. phoenicurus lasted on average for 15‒20 days.

DNA methylation and gene expression changes in mouse pre- and post-implantation embryos generated by intracytoplasmic sperm injection with artificial oocyte activation

Background The application of artificial oocyte activation (AOA) after intracytoplasmic sperm injection (ICSI) is successful in mitigating fertilization failure problems in assisted reproductive technology (ART). Nevertheless, there is no relevant study to investigate whether AOA procedures increase developmental risk by disturbing subsequent gene expression at different embryonic development stages. Methods We used a mouse model to explore the influence of AOA treatment on pre- and post-implantation events. Firstly, the developmental potential of embryos with or without AOA treatment were assessed by the rates of fertilization and blastocyst formation. Secondly, transcriptome high-throughput sequencing was performed among the three groups (ICSI, ICSI-AOA and dICSI-AOA groups). The hierarchical clustering and Principal Component Analysis (PCA) analysis were used. Subsequently, Igf2r/Airn methylation analysis were detected using methylation-specific PCR sequencing following bisulfite treatment. Finally, birth rate and birth weight were examined following mouse embryo transfer. Results The rates of fertilization and blastocyst formation were significantly lower in oocyte activation-deficient sperm injection group (dICSI group) when compared with the ICSI group (30.8 % vs. 84.4 %, 10.0 % vs. 41.5 %). There were 133 differentially expressed genes (DEGs) between the ICSI-AOA group and ICSI group, and 266 DEGs between the dICSI-AOA group and ICSI group. In addition, the imprinted gene, Igf2r is up regulated in AOA treatment group compared to control group. The Igf2r/Airn imprinted expression model demonstrates that AOA treatment stimulates maternal allele-specific mehtylation spreads at differentially methylated region 2, followed by the initiation of paternal imprinted Airn long non-coding (lnc) RNA, resulting in the up regulated expression of Igf2r. Furthermore, the birth weight of newborn mice originating from AOA group was significantly lower compared to that of ICSI group. The pups born following AOA treatment did not show any other abnormalities during early development. All offspring mated successfully with fertile controls. Conclusions AOA treatment affects imprinted gene Igf2r expression and mehtylation states in mouse pre- and post-implantation embryo, which is regulated by the imprinted Airn. Nevertheless, no significant differences were found in post-natal growth of the pups in the present study. It is hoped that this study could provide valuable insights of AOA technology in assisted reproduction biology.

Validation on Real Data of an Extended Embryo-Uterine Probabilistic Graphical Model for Embryo Selection

Embryo selection is a critical step in assisted reproduction (ART): a good selection criteria is expected to increase the probability of inducing pregnancy. In the past, machine learning methods have been used to predict implantation and to rank the most promising embryos. Here, we study the use of a probabilistic graphical model that assumes independence between embryos’ individual features and cycles characteristics. It also accounts for a third source of uncertainty attributed to unknown factors. We present an empirical validation and analysis of the behavior of the model within real data. The dataset describes 604 consecutive ART cycles carried out at Hospital Donostia (Spain), where embryo selection was performed following the Spanish Association for Reproduction Biology Studies (ASEBIR) protocol, based on morphological features. The performance of our model is evaluated with different metrics and the predicted probability densities are examined to obtain significant insights about the process. Special attention is given to the relation between the model and the ASEBIR protocol. We validate our model by showing that its predictions show correlation with the ASEBIR score when the score is not provided as a feature. However, once the selection based on this protocol has taken place, our model is unable to separate implanted and failed embryos when only embryo individual features are used. From here, we can conclude that ASEBIR score provides a good summary of morphological features.

Reproductive behaviour in free-ranging crested porcupine Hystrix cristata L., 1758

Previous data on crested porcupine reproduction biology were mostly collected in captivity or semi-captivity due to its elusive, burrowing and mainly nocturnal habits. Between 2017 and 2019 the reproductive behaviour (i.e., intrapair mounting and copulation, birth and parental care) of free-ranging crested porcupine was documented and described. Nightly rhythms of single and multiple mounting occurred throughout the year while only two copulation events were recorded. Three months after both copulation events, the birth of porcupettes (porcupine < 5 kg) was recorded. A stochastic phase characterized by an articulate courtship with distinct behavioural patterns always preceded each mounting event. After the stochastic phase, the presenting of the female evoked by Nose-Quill contact behaviour, occurred in 83.8% (n = 182) of mounting events, while in 16.1% (n = 35) a spontaneous presenting of the female occurred. The average duration of copulation lasted 24 s (SD = 7 s) with 17 thrusting (SD = 5.5 thrusting). Births of porcupettes occurred throughout the year from 1 to 3 times per pair per year and the litter size observed ranged from 1 to 2 porcupettes. The first emerging of porcupettes from burrow occurred at 10–15 days after birth. Parents and sub-adults of the family actively perform parental care and the permanence of sub-adults within the family (i.e., from birth to dispersal) resulted to be at least 1 year. This investigation provides new useful insights on porcupine reproductive behaviour in the wild. Such new knowledge may be useful to the management of porcupines in wild, semiwild and captive condition as well as to delineate the key habitat desiderata of this rodent.

The Nereid on the rise: Platynereis as a model system

The Nereid Platynereis dumerilii (Audouin and Milne Edwards (Annales des Sciences Naturelles 1:195–269, 1833) is a marine annelid that belongs to the Nereididae, a family of errant polychaete worms. The Nereid shows a pelago-benthic life cycle: as a general characteristic for the superphylum of Lophotrochozoa/Spiralia, it has spirally cleaving embryos developing into swimming trochophore larvae. The larvae then metamorphose into benthic worms living in self-spun tubes on macroalgae. Platynereis is used as a model for genetics, regeneration, reproduction biology, development, evolution, chronobiology, neurobiology, ecology, ecotoxicology, and most recently also for connectomics and single-cell genomics. Research on the Nereid started with studies on eye development and spiralian embryogenesis in the nineteenth and early twentieth centuries. Transitioning into the molecular era, Platynereis research focused on posterior growth and regeneration, neuroendocrinology, circadian and lunar cycles, fertilization, and oocyte maturation. Other work covered segmentation, photoreceptors and other sensory cells, nephridia, and population dynamics. Most recently, the unique advantages of the Nereid young worm for whole-body volume electron microscopy and single-cell sequencing became apparent, enabling the tracing of all neurons in its rope-ladder-like central nervous system, and the construction of multimodal cellular atlases. Here, we provide an overview of current topics and methodologies for P. dumerilii, with the aim of stimulating further interest into our unique model and expanding the active and vibrant Platynereis community.

O-148 Sperm Aminopeptidase N as a predictive biomarker of blastocyst development and embryo viability

Study question To evaluate human sperm APN as a prognostic factor for determining high-quality embryos. Summary answer The human sperm APN has the potential to become new molecular prognostic biomarker for having high-quality and viable embryos. What is known already Prognosis and diagnosis of male fertility is one of the major concerns in reproductive medicine. Approximately 30%-40% of men with otherwise normal fertility parameters are still unable to achieve pregnancy. The predictive clinical value of a semen analysis to identify fertile or infertile males is limited; therefore, new sperm diagnostic or prognostic methodologies are urgently required. Sperm Aminopeptidase N (APN) may be a relevant molecular marker due to its high concentration in sperm cells and its role in sperm physiology, such as motility, acrosome reaction, and embryo development. Study design, size, duration A prospective study that involves a total of 81 couples and 611 embryos who underwent oocyte-donation cycles at the Clínica IVI Bilbao (Spain) between September 2014 and July 2015. Participants/materials, setting, methods This study was set in an assisted reproduction unit and in an academic research laboratory. All semen samples were examined and classified following WHO guidelines. Spermatozoa were isolated from semen on discontinuous colloidal silica gradient (45%-90%) technique. Embryo quality and development were determined according to the Spanish Association of Reproduction Biology Studies (ASEBIR) criteria. Flow cytometry analyses of quantitative and semi-quantitative sperm human APN levels. Main results and the role of chance The obtained results proved that the most evolved and viable blastocysts were associated with low sperm APN levels. Expanding, expanded, hatching/hatched and viable blastocysts come from semen samples which showed lower APN levels than early blastocysts, blocked and non viable blastocyst. The cumulative probability of having more evolved blastyocysts increased 1.38-fold at day 5 and 1.98-fold at day 6 of embryo development as well as the likelihood of having viable embryo increased 1.48-fold when semen samples with low APN levels are used during the ICSI technique. Limitations, reasons for caution Data obtained from a single Fertility Clinic. A multi-centrum study will be required. Wider implications of the findings The human sperm APN has the potential to become new molecular prognostic biomarker for having high-quality embryos that could help to diagnose male infertility, especially when seminal parameters are close to the threshold values. Trial registration number Not applicable

Case Report: Ovulation Induction in Greater One-Horned Rhinoceros (Rhinoceros unicornis)

Despite a profound knowledge on reproduction biology in greater one-horned (GOH) rhinoceros, many individuals cope with sub or infertility or an-ovulatory estrous. At the same time, early and regular captive breeding is of high importance in female GOH rhinoceros due to their high prevalence to develop genital tract tumors with consequent cessation of reproduction. Thus, mature, an-ovulatory GOH rhinoceros represent a challenge for captive breeding programs and warrant for means of reliable ovulation induction. Here, we used hCG and GnRH analog histrelin to induce ovulation in an-ovulatory GOH rhinoceros. Upon ultrasound diagnosis of a preovulatory follicle hCG or GnRH were injected to induce ovulation (n = 11). As a result, 75% of the hCG (n = 6/8) and 33% of GnRH (n = 1/3) inductions resulted in ovulation. Ovulation occurred when fecal estrogen concentration increased before and pregnane concentration after induction. Thirty-six percent of all treatments (n = 4/11) failed to induce ovulation. When ovulation induction by hCG/GnRH injection failed, estrogen and pregnane concentrations were significantly lower compared to ovulatory estrous (P &lt; 0.001). Our results suggest that hCG and GnRH analog facilitate an easily applicable treatment to induce ovulation in females with behavioral but at times an-ovulatory estrous. Frequent use of hCG as an ovulation inducer might help to achieve pregnancies in genetically important but an-ovulatory GOH rhinoceroses.

To the reproduction biology of the Wryneck (Jynx torquilla Linnaeus, 1758) in artificial nests in Northeastern Ukraine

In many countries, the Jynx torquilla population has declined significantly. In Ukraine, the species is considered widespread, but remains poorly studied. Activities to attract birds to parks using artificial nests were carried out during 2004‒2021 in Northeastern Ukraine. The first time the J. torquilla was populated in artificial nests dates back to 2009. During 2019‒2021 4 cases of J. torquilla nesting in artificial nests were recorded. Among the studied territories, the population of J. torquilla in artificial nests was found in the territory of the regional landscape park (RLP) «Feldman Ecopark», NPP «Gomilshansky forests» near the village. Gaidary in Kharkov and the tract «Vakalovschina» near the village Vakalovschina in Sumy regions. In the Northeastern of Ukraine, the number of J. torquilla reaches 14,3±0,32 pairs/km2 in the oak forests of the NPP «Gomilshansky forests» near the village Gaidary, 7,2±0,14 pairs/km2 in the pine forests of the park near the village Zadonetske, 16,2±0,14 pairs/km2 in the «Vakalovschina» tract, 11,1±0,24 pairs/km2 in RLP «Feldman Ecopark». J. torquilla, as a typical hollow-hole, is able to inhabit artificial nests. On average, during 2004–2021, the arrival of the first individuals in the spring was recorded: 21.04 at an average daily temperature of 18° C in the oak grove of the NPP «Gomilshansky forests», 23.04 at a temperature of 17° C in the tract «Vakalovschina», on the territory RLP «Feldman Ecopark» ‒ 02.05 at a temperature of 17° C, 2020 is 05.05 at a temperature of 20° С. It has been proven that 12 days pass from the moment of arrival of birds to the laying of the first egg. The first eggs of birds in the conditions of Northeastern Ukraine, on average, for all years of research, were registered 02.05 in the oak grove of the NPP «Gomilshansky forestsп», 04.05 in the tract «Vakalovschina». On the territory of RLP «Feldman Ecopark» in 2019, the first egg was laid at 14.05 on the material of the nest of the collared flycatcher Ficedula albicollis (Temm., 1815); in 2020 ‒ 19.05. Average clutch size 8,3±0,5 (from 7 to 9). Egg sizes: length – 20,2±0,2 mm, width ‒ 15,1±0,1 mm, volume ‒ 1.4±0.1 mmᶾ, roundness index ‒ 74.7±0.3 %. On average, incubation lasts 13±0,2 days. On the territory of the NPP «Gomilshansky forests» near the village. Gaidary, chicks hatched at 14.05; in the tract «Vakalovschina» on 16.05, on the territory of the RLP «Feldman Ecopark» in 2019 the chicks hatched on 26.05, in 2020 ‒ 01.06. The hatching success was found to be 96,9 % (n=30), where the breeding success is 91,0 %.

Reproduction biology of Abe's flyingfish, Cheilopogon abei Parin, 1996 in Geser East Seram Strait Waters

Eco-biological information of Cheilopogon abei in Geser Streit is unknown. The objective of this research is to observe the sex ratio, first size maturity, gonad maturity and gonado somatic index (GSI) with fecundity of flying fish Ch abei in Geser East Seram Strait waters. Sampling was done for ten months started from February to November 2018, using gill net measuring 1.50 inch. All fish samples were measured in fork length and weighted so dissected to make observations on the level of gonad maturity and the number of eggs in female fish. A total of 682 flying fish was found during the study with a fork length range of 182.6-243.3 mm and a weight of 73.98-115.45 g. The results of the analysis showed that the proportion of the number of male fish was less than that of the female fish for almost every month of observation. The first size gonad mature of male and female is 210.5 mm and 214.1 mm FL. The gonad maturity index of male fish ranges from 0,963-7,967 and female fish ranges 1,315-8,069, the total fecundity is 2321-9438 eggs. Gonads of ripe fish in each month of observation. The spawning peak of Ch abei takes place in June-July and it is hoped that no arrests will be made in both months, to ensure the sustainability of the stock.