Black rockfish(Sebastes schlegeli) is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process...Black rockfish(Sebastes schlegeli) is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process of germ cells in this ovoviviparous rockfish in reproductive season(October 2011–November 2012) with histological methods. We found that the gonad of mature fish showed notable seasonal changes in developmental characteristics and morphological structure. The sperm cells matured during a period lasting from October to December, significantly earlier than the oocytes did. A large number of spermatozoa and other cells occurred in testis at different developmental stages. Vitellogenesis in oocytes began in October, and gestation appeared in April next year. Spermatophores were discovered for the first time in Sebastes, which assembled in testis, main sperm duct, oviduct and genital tract, as well as ovarian cavity in October and April. These organs may serve either as production or hiding places for spermatophores and spermatozoa which were stored and transported in form of spermatophores. Testicular degeneration started from the distal part of testis in April, with spermatophores assembled in degenerating testis and waiting for transportation. The copulation probably lasted for a long period, during which the spermatozoa were discharged in batches as spermatophores. These spermatophores were coated with sticky materials secreted from the interstitial areas of testis and the main sperm duct, then transported into ovary.展开更多
The crucial step of most of the current genetic studies is the extraction of DNA of sufficient quantity and quality.Several genomic DNA isolation methods have been described to successfully obtain male DNA from shrimp...The crucial step of most of the current genetic studies is the extraction of DNA of sufficient quantity and quality.Several genomic DNA isolation methods have been described to successfully obtain male DNA from shrimp species.However,all current protocols require invasive handling methods with males for DNA isolation.Using Aristeus antennatus as a model we tested a reliable non-invasive differential DNA extraction method to male DNA isolation from spermatophores attached to female thelycum.The present protocol provides high quality and quantity DNA for polymerase chain reaction amplification and male genotyping.This new approach could be useful to experimental shrimp culture to select sires with relevant genetic patterns for selective breeding programs.More importantly,it can be applied to identify the mating pairs and male structure in wild populations of species as A.antennatus,where males are often difficult to capture.Our method could be also valuable for biological studies on other spermatophore-using species,such as myriapods,arachnids and insects.展开更多
In addition to sperm,some accessory substances transferred to females during copulation act as nuptial gifts by passing on valuable nutrients in many insect species.The nutritional status of the males can thus have a ...In addition to sperm,some accessory substances transferred to females during copulation act as nuptial gifts by passing on valuable nutrients in many insect species.The nutritional status of the males can thus have a great effect on the mating behavior,fecundity and even the longevity of females.However,little is known about the effect of male nutritional status on the female reproductive traits in migratory insect species,particularly when females experience nutrient shortage and have to choose between reproduction and migration.Here,Cnaphalocrocis medinalis,a migratory rice pest in Asia,was studied to explore this issue.Our results showed that in male moths fed with honey solution,their gonads had higher energy content than gonads of starved males,resulting in increased energy content of the bursa copulatrix of females after mating with fed males.Such females showed increased mating frequency,fecundity and longevity compared to females mating with starved males,indicating that male moths deliver nuptial gifts to females and improve their reproductive performance.However,when females were starved,only about 45%mated,with just a single copulation,regardless of male nutritional status.Starved females showed lower fecundity,and a longer pre-oviposition period(indicating a greater propensity to migrate),compared to fed females.However,copulation still significantly extended their longevity.These results suggest that starved females invest in migration to escape deteriorating habitats,rather than investing the nuptial gift to increased fecundity.Our results further our understanding of the reproductive adaptability of migratory insects under conditions of food stress.展开更多
基金supported financially by Grand Innovating Program of Agriculture Applying Technique in Shandong Province (No. 2008-109)Modern Agricultural Industry Technology System in Shandong Province and the Science and Technology Development Program of Yantai (No. 2013 ZH088)
文摘Black rockfish(Sebastes schlegeli) is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process of germ cells in this ovoviviparous rockfish in reproductive season(October 2011–November 2012) with histological methods. We found that the gonad of mature fish showed notable seasonal changes in developmental characteristics and morphological structure. The sperm cells matured during a period lasting from October to December, significantly earlier than the oocytes did. A large number of spermatozoa and other cells occurred in testis at different developmental stages. Vitellogenesis in oocytes began in October, and gestation appeared in April next year. Spermatophores were discovered for the first time in Sebastes, which assembled in testis, main sperm duct, oviduct and genital tract, as well as ovarian cavity in October and April. These organs may serve either as production or hiding places for spermatophores and spermatozoa which were stored and transported in form of spermatophores. Testicular degeneration started from the distal part of testis in April, with spermatophores assembled in degenerating testis and waiting for transportation. The copulation probably lasted for a long period, during which the spermatozoa were discharged in batches as spermatophores. These spermatophores were coated with sticky materials secreted from the interstitial areas of testis and the main sperm duct, then transported into ovary.
基金supported by a grant from Spanish Ministerio de Economía y Competitividad(CTM2014-54648-C2-2-R)MIR.LP benefited from predoctoral fellowship from the Universitat de Girona(BR2014).
文摘The crucial step of most of the current genetic studies is the extraction of DNA of sufficient quantity and quality.Several genomic DNA isolation methods have been described to successfully obtain male DNA from shrimp species.However,all current protocols require invasive handling methods with males for DNA isolation.Using Aristeus antennatus as a model we tested a reliable non-invasive differential DNA extraction method to male DNA isolation from spermatophores attached to female thelycum.The present protocol provides high quality and quantity DNA for polymerase chain reaction amplification and male genotyping.This new approach could be useful to experimental shrimp culture to select sires with relevant genetic patterns for selective breeding programs.More importantly,it can be applied to identify the mating pairs and male structure in wild populations of species as A.antennatus,where males are often difficult to capture.Our method could be also valuable for biological studies on other spermatophore-using species,such as myriapods,arachnids and insects.
基金supported by the National Key Research and Development Program of China(2016YFD0300702)the Fundamental Research Funds for the Central Universities(China)(KJYQ201902,KJJQ201803).
文摘In addition to sperm,some accessory substances transferred to females during copulation act as nuptial gifts by passing on valuable nutrients in many insect species.The nutritional status of the males can thus have a great effect on the mating behavior,fecundity and even the longevity of females.However,little is known about the effect of male nutritional status on the female reproductive traits in migratory insect species,particularly when females experience nutrient shortage and have to choose between reproduction and migration.Here,Cnaphalocrocis medinalis,a migratory rice pest in Asia,was studied to explore this issue.Our results showed that in male moths fed with honey solution,their gonads had higher energy content than gonads of starved males,resulting in increased energy content of the bursa copulatrix of females after mating with fed males.Such females showed increased mating frequency,fecundity and longevity compared to females mating with starved males,indicating that male moths deliver nuptial gifts to females and improve their reproductive performance.However,when females were starved,only about 45%mated,with just a single copulation,regardless of male nutritional status.Starved females showed lower fecundity,and a longer pre-oviposition period(indicating a greater propensity to migrate),compared to fed females.However,copulation still significantly extended their longevity.These results suggest that starved females invest in migration to escape deteriorating habitats,rather than investing the nuptial gift to increased fecundity.Our results further our understanding of the reproductive adaptability of migratory insects under conditions of food stress.
