Breeding Stage Research Articles

Sex differences in foraging ecology of a zooplanktivorous little auk Alle alle during the pre-laying period: insights from remote sensing and animal-tracking

BackgroundEnergy and time allocation in seabirds differ between consecutive stages of breeding given various requirements of particular phases of the reproductive period. Theses allocations may also be sex-specific considering differential energetic or nutritional requirements of males and females and/or sexual segregation in foraging niches and/or areas. In this study we investigated the foraging ecology of an Arctic, zooplanktivorous seabird, the little auk Alle alle during the pre-laying period using remote sensing of the environment and GPS-TDR loggers deployed on birds. We compared foraging trips range and habitats of birds with other stages of the breeding period and between sexes.ResultsWe found that little auks during the pre-laying period foraged exclusively in cold sea surface temperature zones (with temperatures < 5 ºC) but in various sea depth zones. They dived to similar depths ranging from -4.0 to -10.9 m, exploring various thermal microhabitats (with mean temperatures values ranging from 2.2 °C in Shelf sea depth zone to 5.9 °C in Deep sea depth zone). The majority of foraging trips and dives characteristics were similar to subsequent phases of breeding. However, home ranges during the pre-laying trips were wider compared to the incubation period. As expected, females exhibited wider foraging niches compared to males (wider range of sea surface temperature and sea depth in foraging locations), which could be explained by sex specific energetic and/or nutritional requirements (females producing an egg). We also delineated local foraging areas important for little auks during their whole breeding season. Protection of these areas is crucial for sustaining the local marine biodiversity.ConclusionsWe found that little auks females during the pre-laying period explored wider foraging niches compared to males. These differences may be attributed to sex-specific nutritional or/and energetical constraints at this stage of breeding. The results of this study also emphasize the importance of shelf Arctic-type water masses as the foraging areas for little auks during successive stages of breeding.

Understanding the captive breeding, spawning behavior and early ontogeny of Chromis viridis (Cuvier, 1830): A systematic study

The sustainability of aquarium trade relies on successful captive breeding and seed production practices to prevent the long-term consequences of wild collection, which can result in irreversible damage to natural populations. To establish comprehensive breeding and seed production protocols, it is imperative to gain a deep understanding of the reproductive characteristics of the fish, encompassing aspects such as sexual dimorphism, spawning behavior, embryogenesis, and the crucial period of larval survival. Hence, in this study, we document the captive breeding, spawning behavior, embryonic development, and early larval stages of Chromis viridis, a highly sought-after marine ornamental fish that plays a prominent role in the aquarium trade. Fish were sourced from Agatti Island, Lakshadweep, and reared in controlled conditions. Mature fish (6–9 cm) were kept in 500 L FRP tanks with regulated salinity (35.4 ± 0.5 g/L), temperature (27.1 ± 0.54 °C), and a 12-h light-dark photoperiod. After four months in captivity, spawning commenced, characterized by intense substrate cleaning and rapid swimming motions of the male. Each spawning event yielded 3562 to 20,651 eggs. Egg development included five stages over three days at 27.1 ± 0.54 °C, with hatching on the third day. Egg dimensions varied along both axes and egg volume changed over three days. Newly hatched larvae lacked eye pigments and paired fins, with an average total length (TL) of 1.97 ± 0.35 mm. Larval mouth opening occurred at 38 h, and yolk absorption was complete by the third day post-hatch. Continuous captive reproduction was observed with a spawning frequency of 5.59 ± 0.96 days. This study offers valuable insights for standardizing captive propagation techniques and advancing marine ornamental aquaculture for C. viridis by documenting its breeding, embryonic development, and early larval stages in captivity.

Transcriptome analysis of pigeon pituitary gland: expression changes of genes encoding protein and peptide hormones at different breeding stages

Unlike other poultry, parent pigeons produce "pigeon milk" in their crops to nurture their squabs, which is mainly controlled by prolactin (PRL). Exception for PRL, the pituitary gland may also release various other peptide and protein hormones. However, whether these hormones change during pigeon crop lactation and their potential physiological functions remain unclear. Here, to identify potential peptide or protein hormone genes that regulate crop lactation, we conducted transcriptome analysis of pigeon pituitary glands at 3 different breeding stages (the ceased stage-nonincubation and non-nurturing stage, the 11th d of the incubation, and the 1st d of the nurturing stage) using RNA sequencing (RNA-Seq). Our analysis identified a total of 15,191 mRNAs and screened out 297 differentially expressed genes (DEG), including PRL, VIP, etc. The expression abundance of PRL mRNA on the 1st d of the nurturing stage was respectively 4.93 and 3.62 folds higher when compared to the ceased stage and the 11th d of the incubation stage. Additionally, the expression abundance of VIP is higher in the 1st d of the nurturing stage than in the ceased stage. Protein-protein interaction (PPI) network and Molecular Complex Detection (MCODE) analysis identified several vital DEGs (e.g., GHRHR, VIP, etc.), being closely linked with hormone and enriched in neuropeptide signaling pathway and response to the hormone. Expression pattern analysis revealed that these DEGs exhibited 4 distinct expression patterns (profile 10, 16, 18, 19). Genes in profile 10 and 19 presented a trend with the highest expression level on 1st d of the nurturing stage, and functional enrichment analysis indicated that these genes are involved in neuropeptide hormone activity, receptor-ligand activity, and the extracellular matrix, etc. Taken together, being consistent with PRL, some genes encoding peptide and protein hormones (e.g., VIP) presented differentially expressed in different breeding stages. It suggests that these hormones may be involved in regulation of the crop lactation process or corresponding behavior in domestic pigeons. The results of this study help to gain new insights into the role of pituitary gland in regulating pigeon lactation.

Queen Bee Rearing Trials: Making the Hive to the Production of Queen Cells

With a view to implementing a method of producing and breeding bees to ensure their increase in hives, replace aging queens and create new colonies in the event of desertion, an experimental study of breeding trials of queens of the bees were conducted in the C2GA beekeeping farm (Gassana Gafolai Cooperative of Affem Boussou) in the prefecture of Tchamba, canton of Affem, located 18 km from the town of Tchamba to the East (in the Central region). Given the time of the research internship which was granted to us for the writing of our dissertation with a view to obtaining the Professional License in Agricultural Sciences, this experience only lasted three (03) months. She particularly took into account the first stages of breeding: from the manufacture of the hive to the production of the queen cells. The last stage, which concerns the production of queens, was not reached due to an unfavorable beekeeping season and lack of time. The experiment was carried out on ten (10) Dadant-type hives subjected to three (03) methodologies and distributed as follows: two (02) hives for the grafting method, three (03) hives for the Alley method and five (05) hives for the natural method. The results obtained were more conclusive with the natural method. In fact, only the natural method allowed us to obtain queen cells. This study must be summarized and continued during the different honey flow periods and extended to other farms to better facilitate the choice of the best method of production and breeding of queen bees adapted to Togo.

Analysis of intervarietal soybean hybrids at the initial breeding stages

The results of the study of recombinant soybean hybrids in terms of the degree of heterosis effect, phenotypic dominance and transgressive variability in economically valuable traits with the subsequent selection of the most promising hybrid combinations are presented. The study was conducted from 2018 to 2022 in the laboratory of soybean breeding in the conditions of the steppe zone of the Primorsky Territory. Of the ten hybrid combinations obtained, the maximum effect of heterosis in the first generation was observed in the combinations Primorskaya 1385 × Kofu, Primorskaya 1385 × Dong nong 690, Hei He 38 × Taifun. Phenotypic overdominance of inheritance of indicators (from 1.6 to 76.7) was recorded in all hybrids. Transgressive variability of intervarietal soybean hybrids in the second and third generations varied by combination and generation. High values of the degree of transgression in the third generation were observed in the combinations Primorskaya 1385 × Kofu and Hei He 38 × Talppod-Fisk, in terms of the number of seeds per plant – Primorskaya 1385 × Taifun and Kofu × Taifun, in terms of seed weight per plant – Dong nong 690 × Taifun and Hei He 38 × Taifun. A decrease in the frequency of transgression of hybrids by the third generation was found. The highest values of the degree and frequency of transgression in plant height were observed in the hybrid combinations Hei He 38 × Taifun and Hei He 38 × Talppod-Fisk. Based on the results of the study of the promising soybean genotypes, recombinant hybrids with high productivity and 1000-seed weight in the combinations Kyoto × Dong nong 690 and Monsoon × Taifun were isolated. The hybrids tested had different ripeness groups. Not always the manifestation of high effect of heterosis and transgressive variability in the first – third generations serves as a guarantee of further obtaining samples with high economically valuable indicators.

Individual and environmental factors influencing preen gland's morphology and physiology in the barn owl Tyto alba

Avian preen gland helps birds cope with their environment, although its overall functioning remains unclear. We shed light on the complexity of the preen gland's functioning by studying how multiple factors associate with gland morphology (size and shape) and physiology (wax secreted) in barn owls Tyto alba. Individual factors (sex, breeding stage, body condition) were more important predictors of preen gland than environmental factors (temperature, humidity, brood size). Sex, depending on breeding stage in adults, influenced preen gland traits, pointing to the preen gland's regulation by sex hormones and a greater pressure on females to protect their eggs, offspring and themselves throughout reproduction. Adults and fledglings in better condition had larger glands, pointing to the existence of physiological costs. Temperature and humidity, in interaction with plumage coloration, also influenced but to a lesser extent preen gland traits, suggesting that melanin pigmentation and preen gland act as superseding mechanisms when protecting plumage against microorganisms. Finally, fledglings living in larger broods had larger glands, suggesting a role for the social environment in preen gland's functioning. Overall, our study supports the idea that preen gland functions in diverse biological contexts within the same species and is thus subject to multiple selective pressures.

Study results of the parameters of winter barley adaptability according to forecrops

The development and wide distribution of new adaptive varieties in production is a promising and environmentally friendly way for the development of agriculture. A new, more modern, highly productive variety can ensure increased productivity, resistance of crops to stress factors, and promotes better use of natural and anthropogenic resources. The leading direction in breeding in the nearest future should be not the development of varieties in general, adapted to growing conditions, but the identification of varieties adapted to the stress-limiting environmental factors of a particular region, adaptive to the challenges of nature. In addition to the characteristics of the variety and environmental conditions, the forecrop also influences its productivity. Selection in some conditions may not reveal the potential of the genotype in others, which makes it important to obtain information on different growing environments of varieties at the early stages of breeding. The purpose of the current study was to determine the adaptive properties of promising winter barley varieties and lines according to various forecrops. The study was carried out from 2021 to 2023 to estimate the adaptability parameters of 20 winter barley varieties and lines developed by the FSBSI Agricultural Research Center “Donskoy” for various forecrops (weedfree fallow, peas, sunflower, winter wheat). To determine the indicators of homeostaticity (Hom) and selection value (Sc), stress resistance (Ymin–Ymax) and genetic flexibility ((Ymax+Ymin)/2), the coefficient of responsiveness to favorable growing conditions (Kr) and the indicator of the stability level of the variety (VSLI), there have been applied the methods of V.V. Khangildin and N.A. Litvinenko (1981), A.A. Rosielle and J. Hamblina as presented by A.A. Goncharenko (2005), V.A. Zykin (2005), E.D. Nettevich (2001). According to all forecrops, there have been identified the varieties distinguished by high parameters of environmental adaptability and stability. Stress-resistant genotypes included the lines ‘Parallelum 2016’ and ‘Parallelum 2017’ (Ymin–Ymax = 1.2, 1.1, respectively), which were distinguished by a set of stability indicators and have been recommended for use in the breeding process as sources of high stress resistance, low yield variability, capable of minimizing negative impact of growing conditions. The variety ‘Step’ proved to be adaptable (regression coefficient bi = 1.5), genetically flexible ((Ymin–Ymax)/2 = 7.7), and highly responsive to growing conditions (Kr = 1.53). The dynamics of productivity corresponded to changes in growing conditions, and to maximize a productivity level, there has been recommended to cultivate it on intensive forecrops.

Acoustic ecology of Adélie penguins in the West Antarctic Peninsula

Adélie penguins (Pygoscelis adeliae) are bioindicators for the rapidly changing Antarctic environment, making understanding their population dynamics and behavior of high research priority. However, collecting detailed population data throughout the breeding season on many colonies is difficult due to Antarctica’s harsh conditions and remote location. The colonial breeding ecology of Adélie penguins has led to the evolution of a highly vocal species with individualized calls, making them well-suited for passive acoustic monitoring (PAM) with autonomous recording. PAM units can potentially provide an easily deployable and scalable way to collect fine-scale data on population estimates and breeding phenology. Here I present a framework for using acoustic indices to monitor phenology of dense penguin colonies even under high wind conditions. I evaluate the relationship between acoustic indices such as RMS amplitude and penguin colony size between distinct breeding stages (incubation, guard, crèche, and fledge) on Torgersen and Humble Islands in the West Antarctic Peninsula with an automated pipeline implemented in R. Using PAM to interpret penguin vocalizations for population size and breeding phenology estimates could lead to the development of a real-time remote monitoring system over a large spatial footprint, revealing Adélie penguin responses to climate change.

Genome-wide association and co-expression uncovered ZmMYB71 controls kernel starch content in maize

Starch plays a crucial role as a storage component, greatly affecting the grain yield and quality of maize (Zea mays L.). To meet future demands, it is essential to understand the genetic basis of the natural variation in kernel starch content (SC) for maize breeding. Through a genome-wide association study (GWAS), we identified 84 and 96 loci associated with kernel SC within two years that overlapped with 185 candidate genes. The candidate gene ZmMYB71, which encodes a myeloblastosis (MYB)-related transcription factor, exhibited the highest co-expression frequency with starch synthesis genes. We demonstrated that ZmMYB71 functions as a nuclear located transcription repressor, and the kernel SC of mutants increased by over 2.32%, with a minor effect on amylose content or 100-grain weight. Sh1, Sh2, and GBSSI showed up-regulation in mutants by 1.56-, 1.45- and 1.32-fold, respectively, consistently with the RNA sequencing result; their promoter activities may be directly repressed by ZmMYB71 through the GATATC and TTAGGG motifs. Furthermore, the ZmMYB71 elite haplotype Hap1 was present in over 55% of the high-starch maize sub-populations BSSS and PB but only in 7.14% of the low-starch sub-population PA. Comparing the Hap1 haplotype frequencies in different breeding stages found that its frequency in the inbred group released after 2010 is significantly higher at 40.28%, in contrast to 28.57% and 27.94% in the years 1980 and 1990, and 2000, respectively. The finding provides valuable information on the natural variation in SC of the maize kernel and suggests that ZmMYB71 serves as a negative regulator with the potential to be used to improve SC in the kernels.

Edukasi Masyarakat Jatirejo Mojosongo dalam Meningkatkan Perekonomian melalui Budidaya Maggot Berbasis IoT untuk Pengolahan Sampah Organik

Organic waste makes up the lion's share of solid waste generated by human activities. Therefore, organic waste management efforts are needed to help solve it. One of the efforts that can be made is using BSF larvae to decompose organic waste. BSF larvae or maggots have a high protein and fat content, a chewy texture, and the ability to secrete natural enzymes. BSF females can lay up to 400-800 eggs. After 3-4 days, the eggs will hatch into larvae and consume organic waste, including various types of organic waste such as kitchen, fruits, vegetables, fish, urban, human, and animal waste. The flexibility of BSF larval feed facilitates the cultivation process, and it becomes an ideal insect for decomposing organic waste and becomes a business field because of its fat and protein content. The method of decomposing litter using BSF larvae is quite promising because the opportunities are quite promising, but it is still completely manual. Therefore, IoT-based maggot cultivation, an innovation in maggot cultivation, is needed. IoT design is placed at the maggot breeding stage, with optimal temperature, humidity, and light intensity conditions. This breeding ground is equipped with Arduino, humidity, and temperature sensors to regulate and maintain the best state in each larval breeding process until it becomes a pupa. This design is expected to provide convenience and increase the yield of maggot cultivation.

Common signatures of selection reveal target loci for breeding across soybean populations.

Understanding the underlying genetic bases of yield-related selection and distinguishing these changes from genetic drift are critical for both improved understanding and future success of plant breeding. Soybean [Glycine max (L.) Merr.] is a key species for world food security, yet knowledge of the mechanism of selective breeding in soybean, such as the century-long program of artificial selection in U.S. soybean germplasm, is currently limited to certain genes and loci. Here, we identify genome-wide signatures of selection in separate populations of soybean subjected to artificial selection for increased yield by multiple breeding programs in the United States. We compared the alternative soybean breeding population (AGP) created by USDA-ARS to the conventional public soybean lines (CGP) developed at three different stages of breeding (ancestral, intermediate, and elite) to identify shared signatures of selection and differentiate these from drift. The results showed a strong selection for specific haplotypes identified by single site frequency and haplotype homozygosity methods. A set of common selection signatures was identified in both AGP and CGP that supports the hypothesis that separate breeding programs within similar environments coalesce on the fixation of the same key haplotypes. Signatures unique to each breeding program were observed. These results raise the possibility that selection analysis can allow the identification of favorable alleles to enhance directed breeding approaches.

Early generation clonal selection of sweetpotato (Ipomoea batatas (L.) Lam) using an accelerated breeding scheme

The breeding stages of a clonally propagated crop entails several steps and can take more than five years from hybridisation till cultivar release. The Accelerated Breeding Scheme (ABS) in sweetpotato relies on the use of multiple locations at the early breeding stages to reduce the years required for field evaluation. The aim of the study was to select the best progenies based on the ABS in sweetpotato towards the development of genotypes that combine high protein content with other important agronomic traits. Botanical seeds were generated from crosses between two diverse sets of parents, crossed using a North Carolina II design. F1-progenies (n = 363) were planted in a lattice design at three distinct locations during the 2017/18 planting season. Parameters recorded included pest and disease infestation, storage root traits and yield components, root protein content and nutrient related traits. Nutrient content was determined by near-infrared spectrometry. Analysis of variance and multiple t-distribution test and best test grouping were performed. There were significant differences (p < 0.001) among the genotypes for total number of roots, total root yield, marketable number of roots and marketable yield. The severity of Alternaria blight was significantly higher at Jozini. Forty progenies were selected (12.8% selection pressure) based on agronomic performance. Using the nutrient content results, four promising orange-fleshed clones (NC12-9, NC53-11, NC55-8, NC55-2) and one cream-fleshed clone (NC51-1) were identified with high storage root protein, iron and zinc contents. NC51-1 and NC55-2 produce promising storage root yields. The ABS approach is resource-demanding in the first phase but advances progenies rapidly to the subsequent breeding phases for cultivar release.

Productive performance of elephant grass clones from full-sib families in an advanced stage of breeding

Productive performance of elephant grass clones from full-sib families in an advanced stage of breeding

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.

Molecular Genetic Diversity of Local and Exotic Durum Wheat Genotypes and Their Combining Ability for Agronomic Traits under Water Deficit and Well-Watered Conditions.

Water deficit poses significant environmental stress that adversely affects the growth and productivity of durum wheat. Moreover, projections of climate change suggest an increase in the frequency and severity of droughts, particularly in arid regions. Consequently, there is an urgent need to develop drought-tolerant and high-yielding genotypes to ensure sustained production and global food security in response to population growth. This study aimed to explore the genetic diversity among local and exotic durum wheat genotypes using simple sequence repeat (SSR) markers and, additionally, to explore the combining ability and agronomic performance of assessed durum wheat genotypes and their 28 F1 crosses under normal and drought stress conditions. The investigated SSRs highlighted and confirmed the high genetic variation among the evaluated parental durum wheat genotypes. These diverse eight parental genotypes were consequently used to develop 28 F1s through a diallel mating design. The parental durum genotypes and their developed 28 F1s were assessed under normal and drought stress conditions. The evaluated genotypes were analyzed for their general and specific combining abilities as well as heterosis for agronomic traits under both conditions. The local cultivar Bani-Suef-7 (P8) is maintained as an effective combiner for developing shortened genotypes and improving earliness. Moreover, the local cultivars Bani-Suef-5 (P7) and Bani-Suef-7 (P8) along with the exotic line W1520 (P6) demonstrated excellent general combining ability for improving grain yield and its components under drought stress conditions. Furthermore, valuable specific hybrid combinations, W988 × W994 (P1 × P2), W996 × W1518 (P3 × P5), W1011 × W1520 (P4 × P6), and Bani-Suef-5 × Bani-Suef-7 (P7 × P8), were identified for grain yield and its components under drought stress conditions. The assessed 36 genotypes were grouped according to tolerance indices into five clusters varying from highly drought-sensitive genotypes (group E) to highly drought-tolerant (group A). The genotypes in cluster A (two crosses) followed by thirteen crosses in cluster B displayed higher drought tolerance compared to the other crosses and their parental genotypes. Subsequently, these hybrids could be considered valuable candidates in future durum wheat breeding programs to develop desired segregants under water-deficit conditions. Strong positive relationships were observed between grain yield and number of grains per spike, plant height, and 1000-grain weight under water-deficit conditions. These results highlight the significance of these traits for indirect selection under drought stress conditions, particularly in the early stages of breeding, owing to their convenient measurability.

История селекции рапса ярового во ВНИИМК (обзор)

In USSR, the rapeseed production drown attention only in 70-ties of the last century. In VNIIMK, the full-scale breeding of spring rapeseed had been started by the organization of the laboratory of rapeseed breeding in 1983. The main task at the first stage was development of erucic acid free cultivars. The culti-var Kubansky (type “0”) became the first erucic acid free cultivar of rapeseed, which was differed from the foreign cultivars by the lowered content of linolenic acid in oil – 3.9%. Cultivars developed in 1982–1984 had stable level of erucic acid from 0.2 to 0.8%. The second stage of spring rapeseed breeding covers 1989–1993. It was aimed not only on increasing of oil quality but the cake quality too, namely decreas-ing of glucosinolate content in seeds to 15–16 µmol/g (type “00”). And in parallel, breeding works on in-creasing of oil content in seeds were conducted, as a result this trait meaning was changed from 42.4 to 47.6%. At the next stage in spring rapeseed breeding the main task was to decrease linolenic acid content and increase oleic acid content in oil using intraspecif-ic hybridization, chemical mutagenesis, and self-pollination. The cultivar Viking-VNIIMK had linolen-ic acid content of 4%, and the cultivar Amulet – 77.5% of oleic acid in oil. The new stage in the spring rapeseed breeding is connected with development of yellow-seeded cultivars (type “000”). In 2023, the cultivar Kenar was included into the State register of the breeding achievements. To 2023, a scale of spring rapeseed cultivars of the different usage directions for food and other industries was developed in the institute. The last years, a new stage in spring rapeseed breeding has started, it is aimed on development of interlinear hybrids on CMS base, that do it possible to raise seed yield of this crop on the new level.

Expression dynamics indicate the involvement of SPG7 in the reproduction and spermiogenesis of Phascolosoma esculenta

Spastic paraplegia 7 (SPG7) is an m-AAA protease subunit involved in mitochondrial morphology and physiology. However, its function in animal reproduction is yet to be evaluated. In this study, its molecular features, subcellular localization, and expression dynamics were investigated to analyze its potential function in the reproduction of male Phascolosoma esculenta, an economically important marine species in China. The full-length cDNA of P. esculenta spg7 (Pe-spg7) measures 3053 bp and encodes an 853-amino acid protein (Pe-SPG7). Pe-SPG7 includes two transmembrane domains, an AAA domain and a proteolytic domain. Amino acid sequence alignment revealed that SPG7 was conserved during evolution. The mRNA and protein expression of spg7 indicated its involvement in reproduction. Its expression was the highest in coelomic fluid, where spermatids develop, and it was significantly higher in the breeding stage than in the nonbreeding stage. SPG7 was mainly found in the mitochondria of spermatids in the coelomic fluid, indicating that it functions in this organelle in spermatids. Immunofluorescence experiments showed that SPG7 was expressed and colocalized in the mitochondria during spermiogenesis, suggesting its involvement in P. esculenta spermiogenesis. Therefore, SPG7 may participate in spermiogenesis by functioning in the mitochondria and regulate the reproduction of male P. esculenta. This study provided insights into the function of SPG7 in animal reproduction and P. esculenta gametogenesis.

Integration of Transcriptomics and Proteomics Analysis Reveals the Molecular Mechanism of Eriocheir sinensis Gills Exposed to Heat Stress.

Heat stress is an increasingly concerning topic under global warming. Heat stress can induce organisms to produce excess reactive oxygen species, which will lead to cell damage and destroy the antioxidant defense of aquatic animals. Chinese mitten crab, Eriocheir sinensis, is sensitive to the change in water temperature, and parent crabs are more vulnerable during the breeding stage. In the present study, the multi-omics responses of parent E. sinensis gills to heat stress (24 h) were determined via transcriptome and proteome. The integrative analysis revealed that heat shock protein 70 (HSP70) and glutathione s-transferase (GST) were significantly up-regulated at gene and protein levels after heat stress, indicating that HSP70 and the antioxidant system participated in the regulatory mechanism of heat stress to resist oxidative damage. Moreover, the "Relaxin signaling pathway" was also activated at gene and protein levels under 30 °C stress, which implied that relaxin may be essential and responsible for reducing the oxidative damage of gills caused by extreme heat stress. These findings provided an understanding of the regulation mechanism in E. sinensis under heat stress at gene and protein levels. The mining of key functional genes, proteins, and pathways can also provide a basis for the cultivation of new varieties resistant to oxidative stress.

A vocalization in male Japanese bush warblers in response to both predators and conspecific females

AbstractMale Japanese bush warblers (Cettia diphone) produce not only typical songs but also long, conspicuous vocalizations (continuous songs) during the breeding season. In my preliminary observations, male warblers produced continuous songs in response to both the appearance of a predator and the calls of conspecific females. Although predator‐elicited vocalizations by males have been studied in some species, there are no known cases in which an acoustically identical vocalization is also triggered in response to conspecific females. Here, I examined whether these continuous songs triggered in response to predators and females were acoustically similar. In field experiments, I presented dummies of a Eurasian sparrowhawk and a female warbler before (April) and after (June) female arrival at the breeding ground. Before female arrival, 11.1% of males responded with continuous songs to each of the hawk and female presentations; after female arrival, the respective values were 27.6% and 48.3%. Thus, more males responded to the model presentations with continuous songs after female arrival. There was no difference in the acoustic characteristics of the continuous songs between the two models. The males approached the female model more intensively than the hawk model. These findings do not support the hypothesis that the song functions as an alarm or predator deterrent. The function of these continuous songs remains unclear, but this study is the first to show an example where males produce the same vocalization in response to both predators and conspecific females. The continuous song contains a trill‐like structure, which can be considered a performance‐related song trait. Therefore, the continuous song may possibly be an honest signal of male quality for females. Further studies are required to understand the function of this novel vocalization, particularly the effects of female breeding stage on male singing activity and the female response to the songs.

Assessing the importance of individual‐ and colony‐level variation when using seabird foraging ranges as impact assessment and conservation tools

Knowledge of seabird distributions plays a key role in seabird conservation and sustainable marine management, underpinning efforts to designate protected areas or assess the impact of human developments. Technological advances in animal tracking devices increasingly allow researchers to acquire information on the movement of birds from specific colonies. Nevertheless, most seabird colonies have not been subject to such tracking and another means must be found to assess their likely foraging distribution. Consequently, foraging range data collated and summarized across other tracking studies has often been used to estimate species‐level foraging distances for use within applied settings. However, generic species‐specific foraging ranges must be used with caution because of the amount of variation in seabird foraging behaviour at both the individual and colony levels. Specifically, although current reviews of seabird foraging ranges provide summary estimates of maximum foraging range, they typically do not assess the extent of among‐colony or among‐individual variation around such estimates. To address this, we conducted a variance component analysis of the maximum distance reached from the breeding colony per foraging trip (foraging range) using multi‐colony tracking datasets to estimate the degree of between‐individual, between‐year and between‐colony variation in foraging range in four UK breeding seabirds (Black‐legged Kittiwake Rissa tridactyla, Common Guillemot Uria aalge, Razorbill Alca torda and European Shag Gulosus aristotelis). We also provide updated estimates of typical foraging ranges for each species and quantify the influence of breeding stage and colony size. Overall, between‐colony variation was typically the largest variance component, explaining 20–30% of the observed variation in foraging range across the four species. Individual‐level variation was also relatively large among Shag. In Kittiwake, Guillemot and Shag, but not Razorbill, average foraging ranges were positively associated with colony size. In addition, Kittiwake and Razorbill travelled further during incubation than during chick‐rearing. More generally, our estimates of mean foraging ranges for each species were subject to a high degree of uncertainty, which should be incorporated into impact assessments carried out using such data.