Laser capture microdissection of gonads from juvenile. Early development occurs at a rapid, but predictable rate when the embryos are raised at 28 c. Zebrafish n 5 329 were injected at 6 weeks post fertilization, a booster. From gills to gonads, youre more like a fish than you may. Dissection of larval zebrafish gonadal tissue ncbi. Furthermore, zebrafish embryos are clear, which allows scientists to watch the fertilized eggs grow into fully formed baby fish under a microscope. These embryos have the great advantage that they develop as see through embryos, that is, all internal development can be clearly observed from the outside in the living embryo.
The male gonad, the testicle, produces sperm in the form of spermatozoa. You can also browse the zebrafish anatomical ontology ao to show anatomical terms that are present at that stage. In genital males the medulla develops during seventh and eight. Sex reversal in zebrafish fancl mutants is caused by tp53. Localization of gsdf, gdf9, and cd205 transcripts within the gonad. Zebrafish larva, the stage of development from between three and thirty days postfertilization, grow in length from approximately 3. Here, we study the role of the germ cells in somatic development and particularly the role of the germ line in the sex differentiation in zebrafish. It has been described as a juvenile hermaphrodite because males undergo a juvenile ovarytotestis gonadal transformation process 46. Fish show a striking plasticity of the sex determination process, which is reflected in a wide range of gonad differentiation mechanisms, and includes gonochoristic species as well as hermaphroditic species. Cycle of gonad maturation, condition index and spawning of.
In this study, the oocyte development of the zebrafish was divided to four stages. It is closely associated with the peritoneum between arrows. Sex determination process an overview sciencedirect topics. M any aspects of zebrafish husbandry, including diet, are yet to be standardized. Hardcopies of the 4th edition of the zebrafish book can be obtained for a nominal fee from the zebrafish international resource center, 5274.
Investigating gonadal gene expression is important in attempting to elucidate the molecular mechanism of sex determination and differentiation in the model species zebrafish. Zebrafish early gonad development and sex determination. The zebrafish in toxicologytestis development wikibooks. The zebrafish has become a powerful model and is extensively used in development and diseaserelated research. The female gonad development of the zebrafish was monitored as four phases according to classification. Control of gonad growth, maturation and spawning in teleost fish. The majority 97% of the 3536dayold fish showed protogynic ovaries while one out of the 33 fish examined histologically displayed an undifferentiated. C spermatogenic crypt formation within lamellae of immature ovary from a 67 mm sl fish. Gonad development in the female nigerian clarias gariepinus. Gonad development and vitellogenin production in zebrafish. Morphological development of the gonads in zebrafish, journal. Transition from nonmotile behaviour to directed migration during early pgc development in zebrafish.
Pdf early gonad development in zebrafish danio rerio. Developmental biology, issue 122, dissection, gonads, sex determination, larval zebrafish, immature ovary, immature testis. Gonad development an overview sciencedirect topics. During gonadal development, the gonad may be transiently intersexual where there is a parallel presence of both oocytes and spermatocytes. Pdf sublethal effects of carbaryl on embryonic and.
Molecular mechanisms of cell differentiation in gonad. Gonad and body mass were measured to the nearest 0. The first appearance of the gonad is essentially the same in the two sexes, and consists in a thickening of the mesothelial layer of the peritoneum. It also discusses the processes leading to the testis. Molecular analysis shows differential expression of r. Most mutants were female and the few males often had oocytes in their testes, showing that amh promotes male development. The development of the gonads is part of the prenatal development of the reproductive system and ultimately forms the testes in males and the ovaries in females.
The thick plate of epithelium extends deeply, pushing before it the mesoderm and forming a distinct projection. A and cfemale exposed to fad, showing a gonad similar to a juvenile ovary. Apr 29, 2014 what happens in a human is we begin our development with the gonads in a fish position. Fibroblast growth factor signaling is required for early. Zebrafish sex differentiation and gonad development after. Oocyte development in the zebrafish, danio rerio teleostei. The zebrafish information network zfin is the database of genetic and genomic data for the zebrafish danio rerio as a model organism.
Gonad development was determined histologically by light microscopy. Abundance of early embryonic primordial germ cells. The importance of germ cells for the feminization of gonads is also reported in the zebrafish, danio rerio slanchev et al. Furthermore, the various mutant zebrafish lines arising from such studies would also provide excellent animal models to study the molecular mechanism of gonad development. Anatomy of the 24, 48, 72 and 120 hours zebrafish danio rerio embryo this collection of sections through zebrafish embryos at four different stages of development is thought to provide some help to understand how the zebrafish embryo looks inside. By fusing zebrafish rspo1 with a green fluorescent protein gene, we found that rspo1 is located in the cytosol and golgi apparatus but not the nucleus of fish epithelioma papulosum cyprinid epc cells. Zfin provides a wide array of expertly curated, organized and crossreferenced zebrafish research data. In fact, in zebrafish some experimental data showed that during ovarian. Download for offline reading, highlight, bookmark or take notes while you read fish development and genetics.
The development and maturation of fish gonads are controlled by genetic and environmental factors, and regulated by a molecular network of signals. Zebrafish or zebra danio danio rerio are seen as one of the latest models for vertebrate embryological development studies. Early gonad development in zebrafish danio rerio grace emily okuthe 1, shirley hanrahan 2 and barry collins fabian 3 1 department of zoology, walter sisulu university, pbx1 mthatha, 5117. Jul 22, 2010 zebrafish has become an important model for understanding vertebrate development and human disease, yet the genetic mechanisms that regulate gonad fate to determine zebrafish sex remain elusive. Zebrafish are an important model species in developmental biology. Female sex development and reproductive duct formation. The gonads initially develop from the mesothelial layer of the peritoneum the ovary is differentiated into a central part, the medulla, covered by a surface layer, the germinal epithelium.
In this work, we describe a mutation in the fancl gene that causes zebrafish to develop exclusively as male due to femaletomale sex reversal. Prim number as a function of hours of development at 28. While the mechanisms of this phenomenon in zebrafish ovaries are not well addressed, here it can be seen in the context of an apoptotic regulation. Here we describe a method to produce large numbers of infertile fish by inducing ubiquitous expression of sdf1a in zebrafish embryos resulting in. Information on the reproductive biology of some economically important fish species which. The structural alterations were observed in the zebrafish oocytes during the oocyte development in the histological studies performed. The banded butterflyfish, chaetodon multicinctus garrett, is endemic to the hawaiian islands and johnston atoll burgess 1978 where it occurs on most coral reefs. The zebrafish lifecycle is divided into four major periods. Exposure to ee2 125 ngl resulted in a dosedependent increase in.
An adult zebrafish diet contaminated with chromium reduces. Zebrafish is an undifferentiated gonochorous species with a polygenic sex determination system. Zebrafish is a gonochoristic species, in which each mature individual possesses only ovaries or testes. Gonadogenesis in zebrafish goes through an initial ovarian phase then subsequently into either ovarian or testicular phases. The roles of amh in zebrafish gonad development and sex. Danio rerio commonly known as the zebrafish is a tropical fish belonging to the minnow family cyprinidae, commonly kept in aquaria and used for scientific research. Fish sex could be easily determined in adults by examining.
Genes determining development of the bipotential gonad the gonad is bipotential, capable of forming either a testis or an ovary until about the sixth week of gestation. Zebrafish sex differentiation and gonad development. Gonad, in zoology, primary reproductive gland that produces reproductive cells gametes. Despite this great diversity among fish species, two model systems have been the focus of much attention in the field of gonad development. Due to the small size and dynamic remodeling of the gonadal tissues in the larval zebrafish, isolation. Furthermore, the lack of a genetic sex marker in juvenile zebrafish prevents pooling gonads from. The process whose specific outcome is the progression of the male gonad over time, from its formation to the mature structure.
The early sexual development of zebrafish males is a complicated process, as they first develop a juvenile ovary, that later undergoes a transformation to give way to a testis. First, lets go over the basic steps in zebrafish development. Gonad morphology, histology, and spermatogenesis south. Inducible sterilization of zebrafish by disruption of. Surface trollcaught fish and subsurface longlinecaught fish are differentiated. Gonad development and sex ratio of sharptooth catfish. The inhibition of apoptosis is therefore crucial to the development of the ovary. Saka ba, adeyemo ok 2015 gonad development in the female nigerian clarias gariepinus burchell 1822. Untill the sixth week of development,these structures are identical in both sexes. An important component of many studies of fish reproductive biology is the assessment of the stage of gonad development of individual fish. Dissection of larval zebrafish gonadal tissue protocol. Native to south asia, it is a popular aquarium fish, frequently sold under the trade name zebra danio and thus often called a tropical fish although both tropical and subtropical. In the female of the species the reproductive cells are the egg cells, and in the male the reproductive cells are the sperm.
Feeding protocols vary widely between facilities and can include a combination of live feed andor commercially formulated fish food. To date no sex linked genes have been identified in zebrafish and no sex chromosomes have been. Headtrunk angle as a function of hours of development at 28. A wave of free cytosolic calcium traverses zebrafish eggs on activation. Amh also derives from mature mammalian ovarian follicles, which marks oocyte reserve and characterizes pcos polycystic ovarian syndrome.
However, their potential in reproductive biology research has yet to be realized. Starting with week 5, some fish showed alterations of gonad morphology, including a decrease in the number and size of the oocytes, an enhanced basophilia and irregular shape of the oocytes, and finally their degeneration into. In females, they descend to the level of the uterus. For the zebrafish, not much literature on the gonad morphology is available but a lot of literature on toxicity in gonad of zebrafish. The fish can grow up to 10 kg in weight, and considered against the limited scope of choice of culturable fish species available to fish farmers in this region, a better understanding of its cycle of gonad maturation and spawning could help in the domestication of the fish in the lower river niger and beyond. Morphological development of the gonads in zebrafish. The gonad begins to form when primordial germ cells and somatic gonad precursor cells coalesce during early development. For example, by employing the lhb zebrafish mutant, we have recently demonstrated a factor called insulinlike growth factor 3 as one of the mediators of lh signaling in. Development of bipotential gonads on each side of the embryo,a primitive gonad arises from a genetial ridge,a condensation of tissue near the adrenal gland. Select a stage name below to get a detailed description and images.
We investigated the chronic effects of deltamethrin on gonads by histopathological examination. Determination, differentiation and development of the gonads are important processes in early mammalian development. Then, gfp expression increased in early differentiated female at 30 and 35 dpf to reach a high gfp intensity. Induced autoimmunity against gonadal proteins affects. B and dmale exposed to the mix, presenting a gonad similar to a type i male gonad. A multidisciplinary approach was applied to explore deeper knowledge about the reproductive biology and ecology of the green mussel perna viridis by interlinking among ecological factors, ingested gut plankton, gonad fatty acid profile, and reproductive traits. Pdf gonadogenesis in zebrafish goes through an initial ovarian phase then subsequently into either ovarian or testicular phases. Genetic regulation of mammalian gonad development nature. Gonad development and histology in bagrus bayad cultured in. Mussels were collected throughout the year from the coastal region of the bay of bengal of bangladesh, and the histological analysis. This image represents an early previtellogenic stage in ovary development, with predominant occurrence of early oocyte stages i. The gonadal masculinisation observed in zebrafish following treatment. Deltamethrin is responsible for health and reproduction problems both in mammals and aquatic organisms.
Integral to this second project is the gathering of biological information which, along with commercial catch and effort data, will be used in the development and interpretation of stock assessment models and in determining how the. B early testis development from previously undifferentiated tissue in a 73 mm sl fish. A guide for the laboratory use of zebrafish danio rerio. Studies comparing zebrafish fancl homozygous mutants, which develop exclusively as males that produce functional sperm, to dnd knock down animals, which develop as sterile males without sperm, suggested that it is specifically oocyte survival through meiosis, rather than the mere presence of germ cells, which is required for female gonad differentiation in zebrafish rodriguezmari et al. Lam department of zoology, national university of singapore kent ridge, singapore 0511 introduction despite their great variety of reproductive strategies, a general characteristic. During zebrafish development, a gradient of stromalderived factor 1a sdf1a provides the directional cue that guides the migration of the primordial germ cells pgcs to the gonadal tissue. Immature reproductive tissue that has not undergone final maturation into either testis or ovary. In this study, zebrafish adults were exposed for 15 days to 0. Genetic basis and biotechnological manipulation of sexual dimorphism and sex determination in fish.
This book presents the current state of knowledge on the origin and differentiation of cell lines involved in the development of the vertebrate male and female gonads with particular emphasis on the mouse. Evolution of gonadotropin signaling on gonad development. Author summary the genes involved in the early stages of vertebrate gonad development remain largely undefined. Exposure to ee2 125 ngl resulted in a dosedependent increase in vitellogenin production starting at 2 ngl. Effect of lactobacillus rhamnosus use on zebrafish the fish. Zebrafish danio rerio is a popular toxicological model and has been used extensively to study the effects of endocrinedisrupting chemicals on gonad development and sexual phenotype 24, 30,31,32, 48,49,50,51,52,53,54,55,56,57. Sexual differentiation, gonad development, and spawning. The full life cycle from fertilized egg to adult is a quick 90 days. Although the reason for this irreversibility is still unknown, one hypothesis has been presented to explain it.
As in other vertebrates, the hpg axis of the neuroendocrine system plays a central regulatory role on the reproductive development of fishes. Danio rerio, gonad, mitoticmeiotic transition, development, sex inversion. As a reference for normal gonadal development, hematoxylineosin he staining was also performed. By day 10 of zebrafish development, pgcs have condensed with somatic cells to form the gonad primordia braat et al. Gonadal development in fish fulltext sexual development 2014. The zebrafish and medaka models ebook written by gong zhiyuan, korzh vladimir. These cells then migrate toward the gonad where they differentiate into sperms and eggs. Reproductive studies of the fishes require knowledge of the stage of the gonad development in the teleosts. Gonadosomatic index which is an index of gonad size relative to fish size is a good indicator of gonadal development in fish 2 the percentage of body weight of fish that is used for production of eggs is determined by the gonadosomatic index. Differentiation of gonad tissue in chaetodon multicinctus.
The posterior lateral line primordium, and underlying structures along the flank of the pharyngula. Starting with week 5, some fish showed alterations of gonad morphology, including a decrease in the number and size of the oocytes, an enhanced basophilia and irregular shape of the oocytes, and finally their degeneration into residual bodies. A early ovary development from previously undifferentiated tissue in a 44 mm sl fish. Control of gonad growth, maturation and spawning in teleost. Zebrafish is classified as an undifferentiated gonochoristic species yamamoto, 1969. The zebrafish in toxicologytestis development wikibooks, open. This differential expression may indicate that rspo1 has a roles in zebrafish gonad development and differentiation. Apr 01, 2003 morphological development of the gonads in zebrafish morphological development of the gonads in zebrafish maack, g segner, h. Gonad differentiation in zebrafish is regulated by the. Toxicity of deltamethrin to zebrafish gonads revealed by. Gonad type percentage of 10 zebrafish from control c and probiotic p groups at 3, 6 and 9 weeks post fertilization wpf. The zebrafish is the most important fish model in developmental and genetic analyses. Aromatase modulation alters gonadal differentiation in.
However, the small size of juvenile zebrafish and correspondingly their gonads complicates this type of investigation. To date, three major developmental pathways were shown to be involved with gonad differentiation through the modulation of programmed cell death. Prior to sex determination, the zebrafish gonad, like the mammalian gonad, is bipotential. Sex determination is the process deciding the sex of a developing embryo. A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes sex cells and sex hormones of an organism. Biology free fulltext reproductive biology and ecology. Condensing mesenchyme of the early pectoral fin bud. The zebrafish in toxicologyovary development wikibooks. Use of transgenic reporter lines combined with histological analysis revealed a variation among males in the onset of transformation. The gonads are formed around the anteroposterior level of somite 10, while the putative attraction center that controls bilateral pgc cluster formation at early somitogenesis is located at the level of. The progenitors of the gametes, the primordial germ cells pgcs are typically specified early in the development in positions, which are distinct from the gonad. During development, gfp was expressed in all immature gonads of 20 dpfold zebrafish.
The differentiated gonad g, testis in this image develops from an undifferentiated gonadal anlage, located retroperitoneally in the caudal peritoneal cavity cpc. Jmse free fulltext toxicity of deltamethrin to zebrafish. However, we know little about the signaling events that lead to the subsequent morphogenesis of the early developing gonadal primordium. The methods for isolation of organs in adult zebrafish such as brain, heart, gonad, and kidney, have been well documented23,24,25.
The zebrafish ovary was composed of germ cells at various stages of developmental advancement. For the present study, the histological analysis of gonads in control fish confirmed previous observations that zebrafish is a juvenile hermaphrodite with protogynic gonads, which later develop into ovaries or testes takahashi, 1977, maack and segner, 2003. Testes are thin and ribbonlike in immature fish, and develop. Hardcopies of the 4th edition of the zebrafish book can be obtained for a nominal fee from the zebrafish international resource center, 5274 university of oregon, eugene, or 97403 usa. The initial formation of the bipotential gonad from uncommitted urogenital ridge requires the function of wilms tumor wt1 and steroidogenic factor. In situ hybridization ish targeting transcripts of gsdf, gdf9, and cd205 was performed on sections of 7 monthold zebrafish gonads.
Further development of the gonads in female zebrafish up to week 11 pf was characterized by an increase in gonad size as well as in the number and size of perinucleolar oocytes. The zebrafish is an important and widely used vertebrate model organism in scientific research, for example in drug development, in particular preclinical. Gonads are composed of both germ cells and somatic cells that enclose. Ly75, all essential for early gonad development, were targeted with 5 immunization tests. The mechanisms controlling zebrafish sex determination and differentiation are not known. Fibroblast growth factor signaling is required for early somatic gonad. Aug, 2014 early gonad development in zebrafish danio rerio grace emily okuthe 1, shirley hanrahan 2 and barry collins fabian 3 1 department of zoology, walter sisulu univer sity, pbx1 mthatha, 5117. The author, who is an acknowledged expert in this subject, has drawn together a wealth of information, providing a book which should be bought by all fish biologists.