Localization and Distribution of Testicular Angiotensin I Converting Enzyme (ACE) in Neck and Mid-Piece of Spermatozoa from Infertile Men in Relation to Sperm Motility

Testicular angiotensin converting enzyme (ACE) is known to play an essential role in the male reproduction and fertility. Data about tACE in cases of male infertility are quite scarce, and in this respect we aimed to study localization and distribution of tACE protein in the neck and mid-piece of spermatozoa from pathological samples in relation to sperm motility. The enzyme expression during capacitation and acrosome reaction was quantitatively assessed. In human ejaculated spermatozoa tACE is localized on sperm plasma membrane of the head, the neck and mid-piece of the tail. The immunoreactivity becomes stronger in capacitated spermatozoa followed by a decrease in acrosome reacted sperm. In different cases of semen pathology (oligozoospermia, asthenozoospermia and teratozoospermia) fluorescent signals in the neck and mid-piece are in punctate manner whereas in normozoospermia they were uniformly distributed. The expression area of tACE the neck and mid-piece was decreased in ejaculated and capacitated sperm from pathological semen samples compared to normospermia. Significant positive correlation was established between tACE area and progressive sperm motility, whereas with immotile sperm the correlation was negative. Our data suggest that proper distribution of tACE in the neck and mid-piece is required for normal sperm motility that could be used as a novel biomarker for male infertility.

ON FERTILITY OF BLACK-BACKED SHAD ALOSA KESSLERI KESSLERI (GRIMM, 1887)

The article highlights the results of studying the individual absolute fertility (IAF) of black-backed shad Alosa kessleri kessleri (Grimm, 1887). The data were obtained during the species’ spawning run in the Volga River. A positive correlation was established between IAF and the linear indicators, weight and age of producers. IAF ranged from 38.0 to 333.9 thousand eggs. The average absolute fecundity of herring varied from 38.8 to 259.2 thousand eggs. In the 1970s black-backed shad of 26-42 cm long had fluctuations in the average absolute fecundity from 88.4 to 258.5 thousand eggs. At the present stage, the size range of spawning shoals suggests that maturity in black-backed shad occurs at a body length of 22-45 cm, the reproductive capacity is regulated by early maturation. The results of studies on the fertility of black-backed herring of various lengths in 1 g of ovary have been obtained. There has been registered a wide range of fluctuations in the number of eggs (from 4033 to 14147 pcs). Differences in the size of ovaries indicate a qualitative definiteness of the physiological readiness of females in the pre-spawning period. The fluctuations in the average individual absolute fertility were revealed depending on body weight and age. Fertility in one-size groups and the reproductive capacity of the population as a whole change due to habitat conditions. The conditional indicator of the population fertility was calculated. The results of the obtained fertility data compared with the data of previous years indicate a 1.5-fold decrease in reproductive capacity of the population at the present time, which indicates a stressed state of the reproductive capacity of female species

Mice With Targeted Deletion of ARC Kisspeptin Exhibit Immature Gametogenesis and Impaired Fertility

Hypothalamic kisspeptin is primarily synthesized in two discrete nuclei - the anteroventral periventricular (AVPV) and the arcuate (ARC) nuclei. We have previously developed a selective, conditional ARC kisspeptin knock-out (KO) mouse line, namely the Pdyn-Cre/Kissfl/fl KO mice, that exhibited normal puberty onset in both sexes, but impaired estrous cyclicity and LH pulsatility in Pdyn-Cre/Kissfl/fl KO females. To examine the end-organ effect of the lack of ARC kisspeptin, we examined gametogenesis, gonad morphology, and fertility. Hematoxylin and eosin (H&E) staining of serial-sectioned whole ovaries demonstrated that Pdyn-Cre/Kissfl/fl KO female mice lacked corpora lutea - their ovarian folliculogenesis did not progress beyond antral follicle development, suggesting an ovulatory defect in Pdyn-Cre/Kissfl/fl KO females. 75% of the Pdyn-Cre/Kissfl/fl KO male mice had testes exhibiting a striking decrease in mature sperm in the seminiferous tubules. The remaining 25% showed evidence of mature sperm. Further evidence of a hypogonadal phenotype of the Pdyn-Cre/Kissfl/fl KO mice included the significantly low weight and small size of the ovaries, uteri, and testes when compared to control littermates. In a controlled, continuous mating paradigm with proven WT males, 2-4-month-old Pdyn-Cre/Kissfl/fl KO female mice failed to become pregnant or produce any pups, whereas age-matched WT females exhibited normal pregnancies to term. Thus, Pdyn-Cre/Kissfl/fl KO females have complete infertility. Ongoing studies of male fertility data suggest that Pdyn-Cre/Kissfl/fl KO males are subfertile, in accordance with their variable spermatogenesis phenotype - some KO males sired pups when paired with proven, WT females, whereas other KO males are infertile. Future experiments include assessing the capability of Pdyn-Cre/Kissfl/fl KO mice to respond to chronic, exogenous kisspeptin and GnRH administration to rescue abnormal LH pulsatility and estrous cyclicity in females, as well as the impaired fertility in both sexes.

Trends in Years Spent as Mothers of Young Children: The Role of Completed Fertility, Birth Spacing, and Multiple Partner Fertility

The number of years women spend as mothers of young children likely has implications for women’s lifetime wages, earnings, and time use. Much prior research has pointed to widening education differences in a wide array of family patterns, but none has examined trends in the number of years women spend as mothers of young children. We use retrospective fertility data from the 2014 Survey of Income and Program Participation to show how changes in women’s completed fertility and birth spacing produce trends in years women spend as mothers of children under age six from 1967 to 2017. Despite remarkably parallel declines in completed fertility, growing educational differences in birth spacing produced educational divergence in years spent as mothers of young children. Particularly striking is the finding that increases in birth spacing reversed declines in years spent as mothers for women with less than a high school degree such that they spent more years with young children in the 2010s than in the late 1960s. The increasing prevalence of multiple partner fertility explains some but not all of these trends.

A Comparison of Approaches to Regional Land-Use Capability Analysis for Agricultural Land-Planning

Smallholder agriculture is a major source of income and food for developing nations. With more frequent drought and increasing scarcity of arable land, more accurate land-use planning tools are needed to allocate land resources to support regional agricultural activity. To address this need, we created Land Capability Classification (LCC) system maps using data from two digital soil maps, which were compared with measurements from 1305 field sites in the Dosso region of Niger. Based on these, we developed 250 m gridded maps of LCC values across the region. Across the region, land is severely limited for agricultural use because of low available water-holding capacity (AWC) that limits dry season agricultural potential, especially without irrigation, and requires more frequent irrigation where supplemental water is available. If the AWC limitation is removed in the LCC algorithm (i.e., simulating the use of sufficient irrigation or a much higher and more evenly distributed rainfall), the dominant limitations become less severe and more spatially varied. Finally, we used additional soil fertility data from the field samples to illustrate the value of collecting contemporary data for dynamic soil properties that are critical for crop production, including soil organic carbon, phosphorus and nitrogen.

Natural variation in fertility is correlated with species-wide levels of divergence inCaenorhabditis elegans

ABSTRACTLife history traits underlie the fitness of organisms and are under strong natural selection in the face of environmental challenges. A new mutation that positively impacts a life history trait will likely increase in frequency and become fixed in a population (e.g.selective sweep). The identification of the beneficial alleles that underlie selective sweeps provides insights into the mechanisms that occurred during the evolution of species. In the global population ofCaenorhabditis elegans,we previously identified selective sweeps that have drastically reduced chromosomal-scale genetic diversity in the species. Here, we measured the fertility (viable offspring) of a collection of wildC. elegansstrains, including many recently isolated divergent strains from the Hawaiian islands and found that strains with larger swept genomic regions on multiple chromosomes have significantly higher fertility than strains that do not have evidence of the recent selective sweeps. We used genome-wide association (GWA) mapping to identify three quantitative trait loci (QTL) underlying the fertility variation. Additionally, we mapped previous fertility data of wildC. elegansstrains andC. elegansrecombinant inbred advanced intercross lines (RIAILs) that were grown in various conditions and detected eight QTL across the genome using GWA and linkage mappings. These QTL show the genetic complexity of life history traits such as fertility across this species. Moreover, the haplotype structure in each GWA QTL region revealed correlations with recent selective sweeps in theC. eleganspopulation. North American and European strains had significantly higher fertility than most strains from Hawaii, a hypothesized origin of theC. elegansspecies, suggesting that beneficial alleles that cause increased fertility could underlie the selective sweeps during the worldwide expansion ofC. elegans.

Spatializing the Coffee Yield Model SAFERNAC with Soil Fertility Data Across Tanzania

The aim of this work was to explore the behavior and usability of the new model SAFERNAC over coffee growing areas throughout Tanzania. Soil fertility data from 1,131 georeferenced points in three zones were fed into the model under four distinct approaches – baseline (no input), organic (manure), inorganic (NPK) and combination of manure and mineral fertilizer. The simulated yields were descriptively compared per zone. They were loaded into QGIS 3.2, interpolated using the Inverse Distance Weighting (IDW) algorithm and the resultant raster maps clipped on basis of digitized boundary shapefiles. Baseline yields were effectively computed from 99.2% of the surveyed sites. The model showed high sensitivity to pH, which has a greater influence on P than N or K. Calculated yields decreased in the order Zone 2 > Zone 1 > Zone 3. The difference in yield between NPK 160:80:80 alone and a combination of NPK 80:40:40 (half dose) plus 5 tons manure was neither quantitatively nor spatially significant. SAFERNAC has proved its usability across the Tanzanian coffee soils, in simulating yield of parchment coffee. The combination approach (organic materials and mineral fertilizers) is most appropriate, as it can reduce the fertilizer cost by about 50% without seriously compromising the expected yields.