The mother sporocyst is the least understood digenean life cycle stage. This study provides the first detailed description of the neuromusculature and reproductive apparatus of mother sporocysts in the hemiuroid digenean Bunocotyle progenetica, a monoxenous parasite of White Sea mud snails, using transmission electron microscopy and fluorescent staining for muscles, FMRFamide-related peptides (FaRP), and serotonin (5HT). These parthenitae lack a germinal mass and have only a few germinal elements, which explains their limited reproductive potential. Germinal cells are incorporated into the syncytial brood-cavity lining, asynchronously maturing and forming germinal balls, which develop into rediae within the cavity. Rediae are expelled through a birth canal differentiated into three regions; their expulsion involves coordinated action of circular sphincter muscles and several extrinsic muscles. Sporocysts are highly mobile, with a dense subtegumental network of circular and longitudinal muscles. Subtegumental myocyte reconstruction showed that each perikaryon is linked to several myofibrils. The nervous system, although lacking distinct ganglia, is well-differentiated, with numerous neurons and at least three types of tegumental sensilla. FaRP-immunoreactive (IR) somata surround the birth canal, forming a nerve net around its middle region and two posterior longitudinal nerves. The unusually abundant 5HT-IR neurons are distributed throughout the body, but most lie in the posterior region. 5HT-IR cells form an anterior nerve ring, from which several nerves project anteriorly and two main nerves extend posteriorly, along with additional nerves. The morphology of the studied sporocysts is discussed in the context of current knowledge on the parthenital biology and development in B. progenetica.

This study investigates the accumulation of glycogen, amino acids, and fatty acids in male Mytilus coruscus during different stages of gonadal development and explores their relationships with reproductive processes. Glycogen levels were highest during the resting phase, decreasing progressively during the proliferation and maturation phases. A positive correlation was observed between glycogen and carbon content, indicating a close association between energy storage and metabolic processes. Amino acid content, particularly essential amino acids (EAAs), increased during gonadal development, reflecting the higher demand for protein synthesis and cellular metabolism. Branched-chain amino acids (BCAAs) such as isoleucine, leucine, and lysine were key in activating protein synthesis and supporting gametogenesis. Non-essential amino acids like aspartic acid, glutamic acid, and glycine also accumulate, supporting cellular function and reproductive regulation. Fatty acids, especially unsaturated fatty acids (UFAs) and polyunsaturated fatty acids (PUFAs), progressively accumulated in the testes, highlighting their role in energy supply and membrane integrity during gametogenesis. Phosphorus (P) accumulated in parallel with fatty acids, supporting DNA and RNA synthesis, energy metabolism, and cell membrane function. This study emphasizes the crucial role of these biochemical components in supporting gonadal development in male M. coruscus, providing insights into the metabolic pathways involved in marine bivalve reproduction.

In this study, we describe the ovarian structure and oogenesis up to the final maturation of oocytes of Hypancistrus seideli. A total of sixty females were used for gonadal analysis and subsequently submitted to light and scanning electron microscopy analyses. Four maturation stages were defined: immature, maturing, mature, and spawned. The oocytes were classified into four stages (I–IV), and the presence of atretic oocytes and post-ovulatory follicles was demonstrated. During oocyte development, changes were observed in color, size, and shape, as well as in the formation of the follicular complex. These results may support reproductive management in captivity, since the species has great commercial importance in the international ornamental fish market and lacks established reproductive protocols in aquaculture. To our knowledge, this is the first morphological characterization of oogenesis in this species, providing original and detailed data that may contribute to the development of captive breeding protocols and to reducing pressure on natural stocks.

Plant invader genotype determines much about how the plant establishes, spreads, and impacts receiving habitat and the types of management required to achieve its control. We investigated phenology, vegetative spread, growth and biomass allocation, and response to herbicides of four flowering rush (Butomus umbellatus L.) amplified fragment length polymorphism (AFLP) genotypes (triploid: GT1; diploid: GT3, GT4, GT5) in a multiyear mesocosm experiment. Monthly observations were made over 31 mo to determine whether there were differences in timing of peak plant growth and flowering. We also applied herbicides during years 2 and 3 using imazamox or triclopyr at rates previously determined to be efficacious against B. umbellatus. By the end of year 1, all genotypes spread vegetatively within their containers. From a single sprouted axillary bud (i.e., bulbil), GT4 plants spread to cover nearly 2,000 cm2 in 6 mo. Flowering occurred May through October for all genotypes, but was reduced in years 2 and 3, including almost no flowering in triploid plants after year 1. Maximum leaf abundance occurred in August or September for all genotypes. After one season of growth, biomass was greatest for diploid genotypes, allocated primarily to leaves. However, by year 3, triploid plant biomass was greater than diploid GT4 and GT5, but not GT3. Bulbil production occurred only in diploid genotypes. At the study conclusion, GT4 and GT5 produced nearly 15,000 and 20,000 bulbils each, whereas GT3 plants produced fewer than 5,000 bulbils. Herbicides were effective in reducing biomass, but triploid plants were far more susceptible than diploid plants. Propagule production was generally reduced by herbicides, but rhizome bud production increased 240% in triploid plants treated with imazamox. These results demonstrate (1) the significant capacity for reproduction and spread of B. umbellatus and (2) the importance of investigating differences between lineages of B. umbellatus to inform management and risk assessments.

Globally, numerous infertile couples have been assisted by extensive research on mammalian fertilization and the rapid development of Assisted Reproductive Technology (ART). However, 5%–15% of the couples that are selected for in vitro fertilization (IVF) experience a total fertilization failure (TFF), where no zygotes develop despite oocytes and semen parameters appear to be normal. Notably, an essential early event in fertilization is the binding of spermatozoa to the oocyte’s external envelope, which followed by the spermatozoa-oocyte fusion. Meanwhile, oocyte activation is a crucial cellular process necessary to block polyspermy and start the development of the zygote. Improper membrane fusion of gametes has been demonstrated to be one of the mechanisms of TFF. Moreover, considering the large amount of research on sperm proteins in recent years, thus in this review, we characterize the role and molecular mechanisms of sperm proteins in the three key processes of gamete adhesion and fusion and oocyte activation, which would provide a comprehensive understanding of the role of sperm proteins in fertilization in mammals and a favourable reference for future studies in assisted reproduction due to FF.

Anti-Müllerian hormone (AMH) is a dimeric glycoprotein belonging to the superfamily of the transforming growth factor-β. Due to the discovery of AMH functions, relative to the ovarian function, it is being postulated as being a highly important marker in studies on mammalian reproduction. Therefore, the objective of this review was to describe the role of this hormone in different reproductive aspects of female mammals, taking women, cows, and mares as reference species. The relationship between ovarian reserve and AMH was analysed, and it has been verified that there is a relationship between the latter, the antral follicle count, and the number of primary follicles. AMH concentration has been associated with parameters like the age of the individual, fertility, superovulation treatments and embryo production, and to the reproductive hormone concentration. Also, an association between AMH and female reproduction system diseases, and the fact that AMH is a heritable feature in the cow have also been proven. Recent studies have analysed the role of AMH receptor type 2 since it appears that, together with gonadotropin-releasing hormone, it controls the secretion of gonadotropins. Despite the considerable amount of bibliography on AMH, more studies are needed to complete the information that we have on it, in order to reveal the unknown elements in its action mechanisms.

Since the 1980s, research has linked environmental factors to adult-onset diseases. The DOHaD theory suggests that exposures during development can permanently affect organ function, predisposing individuals to adult diseases. Studies indicate that protein restriction or a high-fat diet (HFD) during this phase impacts adult metabolism since programmed dysfunctions may depend on changes established during puberty, such as the reproductive system. However, there are no studies on the impact of low-protein (LP) or HFD on male testicles during this phase. For this, Male Wistar rats were categorized into three dietary groups: LP (isocaloric low-protein pelletized); HFD; and Control (balanced commercial) until PND 60. This study was approved by the CEUA-UEM. On postnatal day 61, the animals were euthanized for histopathological, sperm count, and oxidative stress assessments in the testis and epididymis. Statistical analyses were conducted following established ethical principles in animal research. The research revealed significant alterations in daily sperm production and transit through the epididymis. Sperm morphology was affected in the experimental groups. Mitochondrial activity increased in the HFD group. Testicular and epididymal histopathology, seminiferous tubule diameter, and germinal epithelium height, as well as the number of Sertoli and Leydig cells, remained unchanged. Stereological analysis revealed tissue remodeling in the epididymis, particularly in the LP group. LP group showed an increase in lipid peroxidation in the oxidative damage test. In conclusion, low-protein and HFD during peripubertal age did not affect postnatal testicular development in rats. However, they impacted sperm quality, potentially affecting fertility and male reproductive system development.

This article first describes shifts in human rights law that have led to improvements in the realization of sexual and reproductive health and rights (SRHR) over the last decade. The article does so, however, with careful attention to the structural factors beyond formal legal mechanisms that may undermine the ability of governments, even with the best of intentions, to fully develop the necessary robust health and justice systems. Second, this article considers two additional factors: the political economy factors that enable or limit the ability of States to realize SRHR, as well as the growing evidence base that supports positive legal transformation.

The explosive increase in life expectancy over the 20th century led to the formulation of multiple gerontological theories. Of these, it is the evolutionary theories of senescence that enjoy the greatest theoretical and empirical support today. It is striking that these models put reproduction at the center of their postulates, an emphasis shared with the Aristotelian and Thomistic doctrines of the living being; this meeting point inspires our model. In particular, we hypothesize that the corporeal living being, precisely because of its mortality, can only fulfill the universal vocation to similitudo Dei through the generation of another living being of the same species. Once this purpose is fulfilled, its biological organization – understood here as a minimal entitative disposition that allows the actualization of matter by substantial form – decays and is exposed to random damage, as predicted by evolutionary models. This gradual decline is what is known as senescence. Such an approach opens up the possibility of addressing aging positively, with an emphasis on organizational prolongation resulting in a healthier old age. At the same time, such a perspective could illuminate our current understanding of biological organization and the pathologies that affect it.