Reproductive Cycle Research Articles

Guidelines on Developmental Toxicity Tests: Brief Insights.

Developmental toxicology is a constantly evolving research field which needs to attend to a complex underlying regulatory network. In order to ensure human health and environmental safety, new substances have to be tested for toxic effects on reproduction and development, before being commercialized. Traditional in vivo mammalian models represent the intricacy of human development and provide more adequately an assessment of the interaction of chemical compounds with the reproductive system. However, in the last years, the directives are to reduce the use of vertebrate animals, promoting their use only as a last resort. Consequently, the interest on the development and validation of alternative tests, able to cover the various aspects of the reproductive cycle, has significantly increased. Reproductive toxicity is probably the most difficult endpoint to be replaced by alternative assays, since it should provide information on mechanism interactions essential for female and male fertility and also knowledge on the animal development during the first phases of its life cycle. This complexity explains the slow progress in implementing alternative models for reproductive toxicity safety assays. Alternative test models may be based on in vitro systems and nonmammalian animal models. Many biological processes have been successfully addressed using in vitro models, opening the possibility to study the interference of teratogenic compounds. Their validation and implementation have lagged behind, in part because of difficulties in establishing their predictability. Nevertheless, the advance toward the process of validation is crucial to replace and reduce the use of living animals. Based on the present state of the art, it is not probable that such testing strategies will completely replace the need to assess reproductive toxicity in vivo in the near future, but they will contribute to reduce animal tests and will provide important information. In this chapter, the approved guidelines for standard methods and alternative methods, according to their regulatory and scientific status, are enumerated and briefly described.

Evolution and gene expression of matrix metalloproteinase gene family during gonadal development in Scatophagus argus.

During the reproductive cycle of Scatophagus argus (S. argus), their gonads undergo degeneration and re-maturation including the degradation of proteins in the extracellular matrix (ECM). Matrix metalloproteinases (MMPs), a family of zinc proteases, play a crucial role in ECM degradation. Our aim was to identify the MMP gene family of S. argus and determine their gene expression levels across various stages of gonadal development. The MMP gene family of S. argus in the genome was identified by using basic Local Alignment Search Tool (BLAST) and HMMER. Phylogenetic tree and synteny analysis were performed to investigate the evolutionary past of the MMP gene family. The gonads of 18 S. argus (9 males and 9 females) were dissected and a quantitative reverse transcription polymerase chain reaction (RT-qPCR) was conducted to investigate the expression levels of MMP genes across different stages of gonadal development. Twenty-three MMP family genes were identified in the genome of S. argus. We divided the MMP gene family into 4 categories and found that teleosts exhibit a higher MMP gene copy number relative to other vertebrates. By sampling S. argus at different stages of gonadal development, we observed an upregulation in relative expression levels of 11 MMP genes in the testis or ovary. Ten MMP genes (mmp2, 9, 14a, 15a, 15b, 16a, 17a, 23b and 24) showed higher mRNA expression in the testis compared to the ovary and mmp28 had higher expression during ovarian development. The tissue distribution results demonstrated that the gills exhibited the lowest relative expression level among all tissues examined. However, 6 genes (mmp2, 9, 14a, 15a, 15b, and 16a) had relatively high expression in all tissues. The result suggested that teleost-special whole genome duplication was mainly responsible for the formation of the MMP gene family in teleosts. Expression patterns of MMP genes indicated that mmp2, 9, 14a, 15a, 15b, 16a, 17a, 23b and 24 played a vital role in testicular development while mmp28 was more important for ovarian development. Limitaion: Further studies are needed to determine their protein expressions in gonadal development and precise mechanism in gonadal differentiation. The study enhances our understanding of the MMP gene family in evolution of teleost and provides valuable insights for further research on MMPs in S. argus.

Canid attacks on sea turtles along the Northeastern Brazilian Coast

Abstract The aim of the present study was to report canid attacks on sea turtles in northeastern Brazil. The study was conducted on the Sergipe-Alagoas Basin coastline between March 2010 and October 2019. Injured-stranded sea turtles or carcasses were recorded through systematic beach monitoring. The specimens were submitted for clinical or postmortem assessments, providing evidence for the identification of injuries caused by canids. In the study period, 9841 stranded sea turtles were recorded, with the diagnosis of canid attacks in 55 (0.55%) events. Lepidochelys olivacea was the species with the largest number of events (90.90%), followed by Chelonia mydas (7.27%), and Caretta caretta (1.81%). The attacked sea turtles were clinically healthy, with a good body score and no apparent diseases; most were in the reproductive stage. The injuries were mainly found on the front flippers, with considerable loss of musculature affecting the brachial plexus, with the rupture of large blood vessels, and in some cases, exposure of the humerus or oesophagus. Thus, these events hampered the reproductive cycle, limiting the egg-laying process and preventing the hatching of hundreds of new turtles. Therefore, mitigating measures should be implemented, addressing the consequences of abandoning pets and their unsupervised presence on beaches.

The efficiency of growing turkey for meat

Today, the most dynamically developing branch of livestock farming is poultry, which makes a major contribution to the country’s food supply. Poultry production is characterized by a short reproduction cycle and a quick return on investment. In the poultry industry, approximately 95% comes from chicken meat, 3% from turkey meat and 2% from other poultry. Turkey meat has high nutritional, taste and culinary qualities. Unfortunately, meat products sold through retail chains are not always of high quality. The purpose of the study was to analyze the quality of meat of turkey grown in home and industrial conditions. To conduct this study we selected samples of broiler turkey meat of BUT-9 type grown in farm and industrial conditions. The research material was white and red meat, which was previously cooled at a temperature of +2+4 degrees for 12 hours. Organoleptic, physicochemical and bacteriological studies were carried out. The chemical composition and the energy characteristics of meat were determined. The obtained data were ensured to comply with the requirements for meat quality. White and red meat that had been selected from home-grown broiler turkeys was less sustainable than meat obtained from industrial turkeys. White and red meat from the home system was less stable during storage at t+2+4°C in terms of such indicators as pH, acidity/oxidability ratio, VFA, amino ammonia nitrogen, protein content, microbiological indicators (total microbial count). Studying the storage conditions of turkey meat at t-12-14°C ensured the preservation of home-grown meat for 72 hours, and industrially grown meat - for 96 hours. Based on the results of the study, the following was established. Productivity rates was higher in the domestic system. The slaughter yield of the domestic type was higher by 8.8% for females and by 0.1% for males in comparison with industrial type.

Reproduction of Marphysa sanguinea Annelida, Polychaeta (Eunicidae), at Mount Edgecombe, Plymouth, near the type locality in Southwest England

Abstract The reproductive cycle of Marphysa sanguinea is described for a population at Mount Edgecombe, Plymouth, near the type location in Southwest England, using a data set obtained previously (October 1999 to September 2000). The species is iteroparous without schizogamy, spawning prior to October 1999 and during a short breeding season in 2000 from end August through September. The sexes are separate with a sex ratio of 1:1. Mature oocytes and spawned eggs are 215 μm in diameter and spermatozoa of the ectaqua sperm type. Mature gametes of both sexes are discharged through paired coelomoducts, and the diploid chromosome number is 28. Proliferation of new coelomic gametes from paired gonads began within a month of spawning and continued for 8–9 months but ovulation was suppressed in June and July. Attempts to undertake fertilisation using spawned oocytes and active spermatozoa were unsuccessful. The size of discharged oocytes suggests a short pelagic larval duration of a few days. This is the first publication about the reproduction of this species, and our results suggest that M. sanguinea is restricted to intertidal areas in SW England, NW France and southern North Sea. The highly synchronised pattern of reproduction observed is not compatible with a quasi-cosmopolitan species range indicating that this species has been mistakenly reported from around the world. Future studies of the genus should combine rigorous taxonomy with observations of reproduction to facilitate comparison among Marphysa spp.

Бетегелі-лерха жусанды қауымдастықтағы (Artemisia lerchiana, Festuca valesiaca) өнімділік процесі

The article presents the results of the study in accordance with the internationally accepted biological program of productivity, intensity of productivity-destructive processes and biological cycle of nitrogen and ash elements in the plant-soil system in the community of common Fescue-Lerh Wormwood (Artemisia lechiana, Festuca valesiaca). The studied area is located in the northeastern part of the Ural plateau in the Shelek district of Western Kazakhstan in a slightly undulating temperate dry-steppe zone with a slope to the valley of the Elek River in the Konchubai gully with dark chestnut carbonate-saline soils. The communities in the studied area are very important in pasture and forage farming. But under the influence of recent anthropogenic factors, vegetation and soil cover in plant communities are undergoing changes, the diversity of plant species is decreasing, biological productivity is decreasing, the circulation of chemical elements is changing, and plants of forage importance are being replaced by weevils. The community of common Fescue-Lerh Wormwood is characterized by moderate desertification, moderate digression. This community has decreased to 70% of the species diversity, and plants of forage importance have declined and have been slowly replaced by plants that are poor in feed. As a result of the effective use of this community can be restored.

FORMATION OF THE YIELD OF THE ABOVE-GROUND MASS OF WHITE SWEETCLOVER IN SINGLE-SPECIES AND COMBINED CROPS IN THE CONDITIONS OF THE RIGHT-BANK FOREST STEPPE OF UKRAINE

FORMATION OF THE YIELD OF THE ABOVE-GROUND MASS OF WHITE SWEETCLOVER IN SINGLE-SPECIES AND COMBINED CROPS IN THE CONDITIONS OF THE RIGHT-BANK FOREST STEPPE OF UKRAINE

РОЛЬ МЕХАНІЗМІВ ЕКОЛОГІЧНОЇ БЕЗПЕКИ У СОЦІАЛЬНО-ЕКОНОМІЧНОМУ РОЗВИТКУ СІЛЬСЬКИХ ТЕРИТОРІЙ

This article examines the impact of environmental security mechanisms on the socio-economic development of rural areas, emphasizing the importance of their integration to ensure sustainable development. The economic and environmental principles that provide for the rational use of resources, production efficiency, biodiversity conservation, pollution reduction and resource conservation are considered. It was emphasized that the pollution and depletion of natural resources continues to threaten the health of the population, ecological safety and economic stability of the state. The problems of legal provision of food security in crisis situations, such as wars or natural disasters, are also considered, with a special focus on price regulation and support for agricultural production. It is emphasized that the creation and application of ecologically acceptable technologies will become a factor in saving the environment. The advantages of introducing environmental safety mechanisms are analyzed. The article emphasizes the need for an integrated approach that takes into account environmental, economic and social factors for the effective implementation of environmental safety mechanisms. It is indicated that agriculture is of special importance in the development of rural areas, because it provides a permanent income to the rural population, creates and controls natural biological cycles, uses and protects natural resources. It is emphasized that one of the directions of diversification of the development of rural areas in conditions of decentralization is the diversification of organizational and legal forms of management. Measures are proposed to promote the creation of new organizational and legal forms of management in order to improve the quality of life of the rural population and ensure the competitiveness of rural areas. The analysis concludes with the importance of rural areas in food security and sustainable development, with a special emphasis on the potential for economic growth and social well-being depending on the state of the environment and effective environmental security systems.

Primary Hydatid Cysts in Rare Sites: A Series of Four Cases

Hydatid disease is caused by the larval stage of the tapeworm Echinococcus granulosus. The definitive hosts include dogs and canines. Humans are accidental hosts and do not play a role in the biological cycle of the worm. The mode of infection is through ingesting food contaminated with dog feces containing gravid proglottids and free eggs, which hatch in the intestine and form larvae. The larvae then penetrate the intestinal wall, enter the bloodstream, and typically settle in the liver followed by the lungs. However, in rare instances, hydatid cysts can occur in various unusual sites throughout the body and even in a disseminated manner, leading to atypical clinical presentations and diagnostic challenges. Hereby, authors report a series of four cases (three males and one female) of hydatid cysts occurring at unusual sites, mainly the brain, kidney, spleen, and lung. The common age group among the observed cases was the second to fourth decade, showing a male predominance. In cases of splenic and renal hydatid cysts, patients presented with intermittent dull aching pain over the left and right flanks, respectively. In both cases, ultrasonography revealed the presence of multiple cysts in the spleen and kidney. In the case of cerebral hydatid cysts, the patient provided a history of short-term memory loss along with a few non specific symptoms, and Magnetic Resonance Imaging (MRI) revealed a hyperintense cystic lesion. In pulmonary hydatid cysts, the patient presented with symptoms of cough, dyspnoea, chest pain, and expectoration. X-ray examination supported the presence of the cyst. Surgery, preferably radical cystectomy, is considered for treatment, and the diagnosis is always confirmed by histopathology.

Biologia comparativa da mosca do mediterrâneo em frutos de carambola e manga

ABSTRACT Ceratitis capitata is a polyphagous species adapted to the most diverse hosts. The life cycle of C. capitata is influenced by the host species in which it develops, and information about its biological data in star fruit is scarce. This study aimed to characterize the biological cycle of C. capitata in star fruit and mango. Portions of 20 g were offered in Petri dishes lined with moistened filter paper to 20 first-instar larvae up to three hours of age. Evaluations were performed daily, quantifying the period and larval survival, pupal viability and mass (puparia weighed at 24 hours of age), longevity, egg-adult period, and fecundity. Larval survival ranged from 89.75% in star fruit to 94.25% in mango. Pupal viability and mass were higher in larvae fed mango. The length of the larval period was not affected by the food substrate. Total and daily fecundities were higher in females from larvae fed mango. Both fruits allowed the complete development of C. capitata, but mango is the most suitable host for its development.

Correlation of Menstrual Irregularities with Thyroid Disorders in Infertile Women

Background: In current era menstrual irregularities are very common problem mainly in adulthood age. It creates a lot of stress not only on the social behavior of females but can also leads to infertility especially if it is related to hormonal imbalance. Among them, thyroid dysfunction can result in reproductive cycle problems like menorrhagia which is commonly seen in hypothyroid females. Objective: The aim of this study was to highlight menstrual disorders & investigate thyroid hormone levels in both fertile & infertile women. As it will help us to evaluate the correlation between menstrual irregularities & hypo- and hyperthyroidism. Study Design: A case control study, patients were analyzed by the help of questionnaire which include history, clinical examination & laboratory investigations. Settings: This clinical study was done in Gynecology Department of Madinah Teaching Hospital, Faisalabad Pakistan. Duration: 6 months from February 2018 to July 2018. Methods: Almost 132 females belonging to 20-35 years of age were selected, among them 86 females were infertile & 46 were fertile. Results: Results were evaluated by SPSS version 20. Most of the infertile women were euthyroid and hyperthyroidism was more common among them. The prevalence of hyperthyroidism and hypothyroidism was about 26.7% and 9.3% respectively. Almost all infertile females with thyroid disorders showed menstrual irregularities. Thyroid hormonal status was also assessed with different types of menstrual disarrays and it was non-significant. Conclusion: Thyroid profile should be recommended to those infertile women who are having menstrual irregularities so that other needless investigations can be avoided. Evaluation of thyroid status in an infertile couple is important and easy. Its treatment is simple and has reversible or preventable effects on subfertility.

A prospective longitudinal study on the elimination trend of rural cutaneous leishmaniasis in southeastern Iran: Climate change, population displacement, and agricultural transition from 1991 to 2021

Leishmaniasis is a complex disease. Any change in weather conditions affects the humans' social and agricultural expansion and, consequently, the parasite's life cycle in terms of ecology, biodiversity, social stigma, and exclusion. This population-based prospective longitudinal investigation was conducted between 1991 and 2021 in a well-defined CL (cutaneous leishmaniasis) focus in Bam County, southeastern Iran. A robust health clinic and health surveillance system were responsible for the ongoing systematic documentation, detection, identification, and management of CL cases. The exponential smoothing method via the state space model was used in the univariate time series. The TTR, smooth, and forecast packages were used in R software. Landsat satellite images from 1991, 2001, 2011, and 2021 were employed in the physical development. During this period, the temperature increased while the rainfall and humidity decreased. The findings showed a downward trend in the standardized drought index. Also, the results showed that climate warming and ecological changes profoundly affected the area's agricultural patterns and topographical features. Furthermore, the last three decades witnessed an elimination trend for zoonotic CL (ZCL) and the predominance of anthroponotic CL (ACL). The present findings showed that the critical factors in the predominance of ACL and elimination of ZCL were rising temperature, drought, migration, unplanned urbanization, earthquake, and agrarian reform. The wall-enclosed palm tree gardens excluded the primary ZCL reservoir host. They controlled the disease while providing suitable conditions for the emergence/re-emergence of ACL in the newly established settlements and the unplanned ecozone. Therefore, robust health infrastructures, sustained financial support, and evidence-based research studies are crucial to facilitating the necessary surveillance, monitoring, and evaluation to control and eliminate the disease.

Keçilerde Laktasyona Fizyolojik Bir Bakış: Derleme

The domesticated species of goats, scientifically known as Capra hircus, have played a significant role in several aspects of human existence over the course of history. These animals have made notable contributions to both individual animal breeding practices and the overall national economy. Their unique meat and milk production, along with their ease of cultivation, distinguish them as noteworthy entities. Goat milk is widely favored by customers due to its hypoallergenic features, low lactose levels, and rich composition. As a result, goat breeding has been prevalent in our country and globally for milk production in animal husbandry. In accordance with the purpose of achieving a high-quality final product, which constitutes a primary goal of animal husbandry, it is important to possess knowledge on certain attributes relating to the animal under cultivation. The aforementioned characteristics pertain to the anatomical composition of the udder and the physiological processes involved in breastfeeding in goats. Lactation physiology encompasses three key processes: mammogenesis, lactogenesis, and galactopoiesis. Mammogenesis refers to the formation of the udder, while lactogenesis involves the secretion of milk. Galactopoiesis, on the other hand, pertains to the maintenance of continuous milk supply. This review will examine the reproductive cycle, physical structure, and developmental aspects of the udder, as well as the many stages of lactation physiology in goats.

Insights into the Cell Division of Neospora caninum.

Neospora caninum is an apicomplexan protozoan parasite responsible for causing neosporosis in a range of animal species. It results in substantial economic losses in the livestock industry and poses significant health risks to companion and wild animals. Central to its survival and pathogenicity is the process of cell division, which remains poorly understood in this parasite. In this study, we explored the cell division of Neospora caninum using a combination of modern and classic imaging tools, emphasizing its pivotal role in perpetuating the parasite's life cycle and contributing to its ability to persist within host organisms. We described the intricacies of endodyogeny in Neospora caninum, detailing the dynamics of the cell assembly and the nuclear division by ultrastructure expansion microscopy and regular confocal microscopy. Furthermore, we explored the centrosome dynamics, the centrioles and the apicoplast through the advancement of the cell cycle. Our analysis described with unprecedented detail, the endodyogeny in this parasite. By advancing our understanding of these molecular mechanisms, we aimed to inspire innovative strategies for disease management and control, with the ultimate goal of mitigating the devastating impact of neosporosis on animal health and welfare.

Husbandry conditions of spotted ratfish (Hydrolagus colliei, Chimaeriformes) in aquaria for successful embryonic development and long-term survival of juveniles.

The spotted ratfish Hydrolagus colliei is the most common holocephalan species exhibited in aquaria worldwide for introducing deep-sea environments and raising awareness of their conservation. However, little is known about the biology of H. colliei. Current practices in aquaria allow long-term survival of sexually mature H. colliei specimens; however, this species struggles to complete a reproductive cycle in captivity mostly because embryos do not reach the hatchling stage. The aquarists of Planet Ocean Montpellier (POM, France) have bred H. colliei for 15 years and recorded parameters suitable for this species' successful embryonic and post-embryonic development. POM aquarists now regularly record egg-laying events of H. colliei and use four tanks to incubate eggs and raise neonates, late hatchlings, early and intermediate juveniles, subadults, and sexually mature specimens. In this work we provide the first long-term biometric data on H. colliei from the hatchling to the subadult stage. We also report the biotic and abiotic parameters sufficient to breed H. colliei in aquaria. We finally describe the methods used to facilitate individual monitoring of specimens along the ontogeny and several pathologies identified in this species, their putative causes, and the corresponding treatments. This work highlights the importance of ex situ research and points to the valuable outcomes of collaborative efforts between aquaria and academia in deciphering the biology of species whose study in the wild remains challenging.

Effect of Cultivar on Faba Bean–Wheat Intercrop Productivity under a Mediterranean Environment

The term intercropping is used to describe agricultural systems where at least two or more species are cultivated in the same field for a portion of their biological cycle. It is an ancient agricultural practice that, with the evolution of agriculture, the prevalence of intensive cultivation systems, and the use of multiple inputs became mostly restricted to developing countries. However, due to climate instability and uncertainty about weather conditions, interest in intercropping has been revived in recent years. The objective of the present study was to determine which faba bean cultivar can be used with wheat cultivars to achieve higher yields and to examine the interaction between the cultivars in intercropping systems. It was found that the combination of Flamenko with Polycarpi gave the highest yield and showed complementarity in the interaction between these cultivars that also have the highest yield; also, the other indices that were used showed a good response on the intercropping system and the LER was 1.30 and 1.19 for the first and the second year of the study, respectively. Therefore, there are faba bean and wheat cultivars that are better adapted to intercropping conditions and can be utilized by farmers to enhance productivity.

MARKETING RESEARCH OF CONSUMER BEHAVIOUR IN A DIGITAL INFRASTRUCTURE ENVIRONMENT

The article is devoted to marketing research on consumer behaviour in the environment of digital infrastructure. It has been established that marketing research of consumer behaviour in the environment of digital infrastructure models strong systems of interaction with consumers by accurately defining their needs and requests, individualising products and services, operational tracking, and responding to the behaviour of each specific consumer. Research has shown that in a digital infrastructure environment, price is not the primary factor determining choice. First of all, the consumer correlates the characteristics and properties of the goods with his ideal ideas about them (the standard of consumer properties), and in the event of a match, he proceeds to evaluate the possibilities of its purchase, taking into account the price and available income. It has been proven that the environment of the digital infrastructure determines a rational consumer choice under the conditions of a high speed of the reproduction cycle, which singles out time as the main valuable resource, which is associated with the growth of alternative costs of the consumer demand formation process and its implementation. It was found that the development of digitalization has an ambiguous effect on the behaviour of the modern consumer: on the one hand, the possibilities of consumer access to new goods and services are expanding in the shortest possible time, and on the other hand, the level of consumer requirements is increasing, which increases competition between manufacturers and stimulates them to search for new forms of interaction with the consumer. The stages of making a purchase decision by a consumer and the possibility of influence on their opinion by digitalization tools are outlined: awareness of the need, search for information on how to solve problems, evaluation of found solutions to the problem, purchase decision, reaction to the purchase. The elements of digitalization strategies for purchasing behaviour in the context of digital transformation are defined. The services of digital presentation of the product and delivery of goods have been updated, and the frequency of online purchases has increased due to changes in the structure of consumption. It has been proven that the active development of digital technologies and methods of their use necessitated an evolutionary transition from the category of e-services to “digital services”, which take into account the complex influence of the Internet and accompanying digital technologies on the formation of modern business models of companies and the format of their interaction with product consumers and services.

Improving treatment of women with schizophrenia: a review of the recent literature

Effective clinical management of women with schizophrenia is therapeutically challenging. While there have been recent advances in the understanding of neurobiological, hormonal, and female reproductive cycle factors that play a decisive role in the development and progression of schizophrenia in women, this knowledge has not yet been fully translated into treatment practice. The aim was to apply the best evidence available to optimally treat women with schizophrenia at various periods of the lifespan. A narrative review was conducted of recent advances (2018–2023) in aspects of schizophrenia in women that demand sex-specific treatment. Sex steroids impact antipsychotic absorption, distribution, metabolism, elimination, passage through the blood-brain barrier, and blood flow rate to the brain. For these reasons, premenopausal women with schizophrenia, as compared to male age peers, require lower doses of most antipsychotic drugs and suffer comparatively more adverse events (metabolic, sexual, and cardiovascular) at similar doses. Apart from pharmacologic treatment, women have specific reproductive planning needs and need protection from sexual exploitation and domestic abuse. In addition, when pregnant, schizophrenia women show a high risk of gestational diabetes and pre-eclampsia/eclampsia that requires prevention. Prevention is also needed against long-term health hazards for their offspring. Another period of therapeutic challenge specific to women is menopause. The collected evidence points to women-specific recommendations for both biological and psychosocial treatment strategies for schizophrenia.

Regulatory effects of prolactin in amphibians

Prolactin (PRL) is a protein hormone of the anterior pituitary and has a diverse role in different aspects of amphibian life - in courtship, reproduction, larval development and in other physiological functions. The expression of PRL receptor mRNA is reported in skin, gill, liver, gut, kidney, gonads and many other organs of different groups of amphibians. PRL stimulates growth and inhibits the metamorphosis of larvae of several species of amphibians. PRL causes seasonal changes in sex accessory structures and secondary sexual characteristics. PRL affects metabolic regulation and suggests phylogenic conservation of its receptors. Plasma PRL concentration changes during the annual reproductive cycle in many amphibians. In courtship behavior of newt, PRL also induces the synthesis of the newt courtship pheromones. PRL acts on skin and its function is also associated with water drive in amphibians. PRL causes water retention in amphibians. PRL acts centrally or peripherally to induce the courtship behavior. The key goal of the paper is to understand the roles of PRL in various aspect of amphibian life, like in aspects of morphology, behaviour, physiological functions and how PRL interfere amphibian life in presence and absence of other chemical and biological factors.

Comprehensive Transcriptomic and Metabolomic Analysis Revealed the Functional Differences in Pigeon Lactation between Male and Female during the Reproductive Cycle.

Lactation is a unique reproductive behavior in pigeons, with the crop serving as the organ responsible for secreting pigeon milk. Both male and female pigeons can produce crop milk and rear their offspring through a division of labor. Since the time of the secretion of pigeon crop milk is different in the process of feeding the young, whether the metabolism and formation of pigeon milk use the same mechanism is a very interesting scientific question. However, the metabolic dynamics and underlying genetic mechanisms involved in the formation of pigeon crop milk remain unclear, particularly during the incubation-feeding reproductive cycle. In this study, we integrated lactation-associated metabolism and transcriptome data from the crop tissues of both male and female pigeons during the brooding and feeding stages. We mapped the changes in metabolites related to milk formation in the crop tissues during these stages. Through metabolome profiling, we identified 1413 metabolites among 18 crop tissues. During the breeding cycles, the concentrations of estrone, L-ergothioneine, and L-histidine exhibited the most dynamic changes in females. In contrast, estrone, L-anserine, 1-methylhistidine, homovanillate, oxidized glutathione, and reducing glutathione showed the most dynamic changes in males. Gender-specific differences were observed in the metabolome, with several metabolites significantly differing between males and females, many of which were correlated with cytokine binding, immunity, and cytochrome P450 activity. Using this dataset, we constructed complex regulatory networks, enabling us to identify important metabolites and key genes involved in regulating the formation of pigeon milk in male and female pigeons, respectively. Additionally, we investigated gender-associated differences in the crop metabolites of pigeons. Our study revealed differences in the modulation of pigeon crop milk metabolism between males and females and shed light on the potential functions of male and female pigeon milk in the growth, development, and immunity of young pigeons, an area that has not been previously explored. In conclusion, our results provide new insights into the metabolic regulation of pigeon crop milk formation during the brooding and breeding stages. Furthermore, our findings lay the foundation for the accurate development of artificial pigeon milk.