Gonadal Structure Research Articles

Sex ratio and first maturity of blackeye thicklip wrasse Hemigymnus melapterus Bloch, 1791 in Spermonde Archipelago

Blackeye thicklip wrasse Hemigymnus melapterus is a Labridae that was widespread throughout the tropical and subtropical waters of Indo-Pacific. In eastern Indonesia, blackeye thicklip wrasse found from the Strait of Bali, Mentawai Islands, Raja Ampat Islands, Manado and surrounding areas, and Banggai; while in central Indonesia, blackeye thicklip wrasse found in the waters of the Spermonde Archipelago. This research aims to analyze the sex ratio, gonad maturity stage, and the size at first maturity of blackeye thicklip wrasse in the Spermonde Archipelago. This research was done on the population of blackeye thicklip wrasse in the Spermonde Archipelago, South Sulawesi, Indonesia. Samples were collected from fishermen caught landed in the Rajawali Makassar Fisheries Port at Makassar City. Blackeye thicklip wrasse sex ratio was not balanced. This imbalance was thought to have something to do with the “r” reproductive strategy where blackeye thicklip wrasse tries to produce as many eggs as possible to maintain its population. The success of this strategy probably supported by protogyny reproduction patterns where young fish can produce eggs as fast and as much as possible before being devoured by predators. Based on its gonad structure, blackeye thicklip wrasse could be classified as fish with a total spawning pattern that take place long spawning period or individual different spawning period throughout the year. The size at the first maturity of blackeye thicklip wrasse female was 21.4 cm; it was much smaller than half the size that has ever been caught.

Impact of Oral Supplementation of Different Levels of Tamoxifen on Productive and Reproductive Efficiencies and Carcass Traits of Avian48 and Arbor Acres Broilers.

Simple SummaryThe effect of oral supplementation of Tamoxifen on productive and reproductive efficiencies and carcass characteristics of two broiler breeds was investigated in the current study. Tamoxifen supplementation can improve growth performance and carcass efficiency of broilers without changing the sex hormonal profile, however, treatment of broiler chicken with Tamoxifen in different doses caused a gradual decrease in follicle production rate and eventually led to an increase of the atretic follicles in different stages of atresia. Further research is required to estimate the best concentration required for each breed.This research was aimed at estimating the effect of oral supplementation of Tamoxifen on productive efficiency, carcass characteristics, hormonal profile and gonadal structure of two broiler breeds. One hundred and eighty chicks of each breed of Avian48 and Arbor Acres were divided into three groups: control group; TAM10 group, supplied with 10 mg Tamoxifen/kg of body weight at 3, 5, 7 and 9 days of life; and TAM20 group, supplied at the same intervals with 20 mg Tamoxifen/kg of body weight. Both levels of Tamoxifen improved productive performance at early ages, but Arbor Acres produced better results with TAM20 levels than TAM10, while Avian48 breeds reacted adversely. On the contrary, Tamoxifen supplementation significantly decreased feed intake and feed conversion (after the first two weeks of life) compared to control with a higher level of decrease reported for TAM20 treatments than TAM10 and for Arbor Acres compared to Avian48 breed. Carcass traits were not affected significantly with Tamoxifen supplementation compared to control although Arbor Acres responded better to TAM20 and Avian48 for TAM10. With regard to the effect of Tamoxifen (TAM) on sex hormones, it could be concluded that TAM10 treatments showed a stimulating effect on the level of such hormones as compared with the TAM20 group with the most favourable results being clearly detectable in 42-day-old birds although both concentrations of Tamoxifen did not differ significantly from control. However, treatment of broiler chickens with Tamoxifen in different doses caused a gradual decrease in follicle production rate and eventually led to an increase of the atretic follicles in different stages of atresia. Finally, we can conclude that Tamoxifen supplementation can improve performance and carcass efficiency of broilers without changing the hormonal profile, however much research is required to estimate the best concentration required for each breed.

Reproductive development of the priapium fish Neosthetus lankesteri Regan, 1916 (Atheriniformes: Phallosthethidae) from Pranburi river estuary, Thailand using the histological approach

Reproduction in the family Phallostethidae is an area that has long been of interest especially in gonadal structure and gametogenesis. However, no published data concerning as mentioned above in Neostethus lankesteri Regan, 1916 from Thailand is noted. This fish is important for rural livelihood in the estuarine fisheries of Pranburi River estuary, Thailand. The construction of the female reproductive system of N. lankesteri composed of the ovary and short oviduct. The mature ovarian morphology is a single organ, which is histologically considered to be an asynchronous development ovary. The differentiating oocytes were observed and classified into oogonia proliferation, primary growth phase, secondary growth phase, post-ovulatory phase and atretic follicle phase. Under the ovarian differentiation, our observation indicated that the ovarian parenchyma of N. lankesteri during 1.8 – 2.4 cm in standard length (SL) was accompanied by the secondary growth phases. Identification of the post-ovulatory phase was detected during our sampling periods, indicating to entire life in the Pranburi River estuary as well as true resident species. In the male reproductive system of N. lankesteri, the mature testicular parenchyma was organized morphologically as a single organ and histologically appeared to be a restricted spermatogonial lobular testis type. The differentiation of the spermatogenetic stage was composed of three phases including spermatogonial, spermatocyte and spermiogenetic phases. It was to identify possible trends that the size at first maturity of the female fish was estimated at 1.8 cm SL. Certainly, results from this study clearly showed on the reproductive pattern of N. lankesteri, which could be applied to further studies (the reproductive cycle, spawning season and histopathology).

Chronology of Gonadal Development in the Malayan Snail-eating Turtle Malayemys macrocephala.

The snail-eating turtle, Malayemys macrocephala, is a common freshwater turtle that can be used as an animal model for developmental biology. However, a thorough investigation of its development is needed before this species can be used as a model. Thus, this study aimed to examine the gonadal development of M. macrocephala. Turtle eggs were collected from rice fields in Phra Nakhon Si Ayutthaya Province, Thailand, and transported to the laboratory. Eggs were incubated in microprocessor-controlled incubators and randomly dissected on a weekly basis to reveal the developing embryos, then their developmental stage was identified according to Yntema (1968). Primordial germ cells and gonad structure were processed through the paraffin method. Moreover, the dynamics of germ cell proliferation and apoptosis were examined by immunohistochemical detection of proliferating cell nuclear antigen (PCNA) and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), respectively. Examination of the gonad revealed four main stages of gonadal development: (i) germ cell migration, (ii) genital ridge appearance, (iii) testicular formation, and (iv) ovarian formation. In the male turtle (incubated at 26°C), gonad developed into the testis with medullary sex cords starting at Yntema stage 17. In the female turtle (incubated at 32°C), these sex cords then degenerated, followed by cortical development into an ovarian structure starting at Yntema stage 19. Subsequently, testicular and ovarian development occurred independently, and distinct sex organs were apparent at Yntema stage 25. In addition, the presumptive testis showed germ cell proliferation in the medulla at Yntema stages 17, 19, and 25 and germ cell apoptosis in the cortex at Yntema stages 19 and 25. The presumptive ovary showed germ cell proliferation in the cortex at Yntema stages 19 and 25, and germ cell apoptosis in the medulla at Yntema stages 19 and 25.

Gonadal Maturation and Main Spawning Period of Haliotis gigantea (Gastropoda: Haliotidae).

This study was carried out to obtain information on the developmental biology and the management of biological resources of the abalone Haliotis gigantea in Korea. The sex ratio (female:male) in the present study was 1:1.7 and the proportion of females was 36.6% (n=106/290). Their gonadal structures displayed definitive seasonal changes which were similar in pattern to the changes in the gonad index (GI). The GI showed a pattern of definitive seasonal changes in both males and females it was high in the fall and low in the spring. The reproductive cycle could be categorized into the following six stages: inactive, early active, late active, ripe, spent, and degenerative stage. Based on the monthly changes in GI and stages of gonadal development, October to November was determined to be the main spawning period for H. gigantea on Jeju Island, Korea.

Changes in ovary and testis and breeding fitness of the climbing perch, Anabas testudineus (Bloch, 1792), exposed to sub‐lethal concentrations of monocrotophos

Monocrotophos (MCP) is one of the organophosphate pesticides extensively used in agriculture and animal husbandry. The present study reports the effects of sub-lethal concentrations of MCP on gonadosomatic index (GSI), gonadal histology and breeding fitness of the fish Anabas testudineus. The fish were exposed to three sub-lethal concentrations of monocrotophos (T1: 3.5 mg/L, T2: 5.3 mg/L and T3: 10.6 mg/L) for 45 days with 12 fish (males and females in equal numbers) in each tank, and one group was kept as control (C) without any treatment. GSI decreased in all treatment groups in comparison with control. Significant decrease in fertilization and hatching rate was observed at all concentrations in comparison with control on 15, 30 and 45 days of monocrotophos exposure. The decreased vitellogenesis, disruption of follicular wall and oocyte atresia were observed in all the treated females at 30 and 45 days of exposure. Rupture of seminiferous tubules was noticed in all the treated males irrespective of exposure periods. The results thus indicated that monocrotophos could deleteriously impact the gonadal structure and function in A. testudineus, which could seriously impact the reproductive success of the animal.

Some Data on Reproductive Biology of Spotted Ghoul Inimicus sinensis (Synanceiidae)

Gonadal structure, cytological condition of oocytes, ultrastructure of egg envelope, and spermatozoa morphology are studied in the individuals of Inimicus sinensis 120–230 mm TL with the gonads mainly at maturity stage IV. The males possess hypertrophied urinary bladders. Based on oocytes’ size distribution in the ovaries, the oogenesis is continuous and the spawning is multiple. Oocytes of the maturation period are 600–700 µm in diameter. The batch fecundity is 15 380 oocytes on average. The zona radiata of oocytes that have completed growth is 10.2 µm in width on average and it consists of two layers. The narrow outermost layer of the egg envelope approximately 0.34 µm width is most likely chorion. Spermatozoon ultrastructure of I. sinensis does not notably differ from that in other representatives of the suborder Scorpaenoidei with external insemination. The centriolar complex is characterized by orthogonal position of centrioles. Based on ovarian structure, the representatives of the genus Inimicus do not differ from the majority of teleost fishes and viviparous species of the genera Sebastes and Sebastiscus. However, many representatives of the suborder Scorpaenoidei have unique ovarian structure with the central ovigerous stroma attached to the anterior part of the ovary. Based on the current phylogenetic schemes, this ovarian type evolved independently in several evolutionary lineages.

Spatial and temporal expression pattern of sex-related genes in ovo-testis of the self-fertilizing mangrove killifish (Kryptolebias marmoratus).

In vertebrates, sex determination and differentiation comprehend a fine balance between female and male factors, leading the bipotential anlage to develop towards ovary or testis, respectively. Nevertheless, the mangrove killifish, (Kryptolebias marmoratus) a simultaneous hermaphroditic species, could overcome those antagonistic pathways and evolved to develop and maintain reproductively active ovarian and testicular tissues in the same organ. Morphological and mRNA localization analyzes of developing and adult gonads demonstrate that genes related to testis (dmrt1 and amh) and ovary differentiation (foxl2 and sox9a) follow the same expression pattern observed in gonochoristic species, thus functioning as two independent organs. In addition, Amh expression patterns make it a strong candidate for initiation of the formation and maintenance of the testicular tissue in the hermaphroditic gonad. Differently from described so far, foxl3 seems to have an important role in oogenesis as well as spermatogenesis and gonadal structure.

The Reproductive Cycle of Holothuria Cucumaria frondosa of the Barents Sea

The study considers the morphological features of the gonad structure and the seasonal changes in the reproductive activity of the gonads of holothuria Cucumaria frondosa of the Barents Sea. The sex of individuals can be identified using morphometric analysis with the average mass of gonads of 1.63 g, with the average mass of the skin-muscle sac of 53.00 g and the length of 80.00-83.00 mm whereas the diameter of the genital tubes is not less than 0.50 mm. The spawning of cucumaria, producing plankton progeny, occurs from March to May, but the spawning period can be shifted, since the beginning of the spawning period is associated with the seasonal increase of the surface water temperature and the intensive phytoplankton blooming. The character of spawning is intermittent. Individual fertility is low, in individuals with the average mass of SMS 150.00-200.00 g ranged from 9 to 32 thousand cells.

Long-term maternal exposure to atrazine in the drinking water reduces penis length in the tammar wallaby Macropus eugenii

Marsupials are experiencing devastating population declines across Australia. Exposure to environmental endocrine disruptors, through ingestion of contaminated resources in the environment, could be contributing to this decline. Atrazine (ATZ), a widely used herbicide in Australia, is an endocrine disruptor with the ability to cause reproductive abnormalities in a diverse range of vertebrates. We exposed adult female wallabies (Macropus eugenii) to drinking water containing ATZ (450 p.p.m) throughout pregnancy, parturition and lactation. We assessed the outcome of this exposure to the reproductive development of their young by assessing gonad and phallus development. Both these organs are especially sensitive to perturbations in the hormonal environment during development. Although no gross abnormalities were seen in gonad structure, exposure to ATZ did alter the expression of genes required for normal testis function. Furthermore, long-term exposure to ATZ resulted in a significant reduction in penis length. These results demonstrate that ATZ exposure during gestation and lactation can significantly affect the development of male young by affecting virilisation. Given the known vulnerability of macropodid marsupials to endocrine disruption, as well as their overlapping distribution with agricultural areas, these data raise major concerns for the use of pesticides in areas with fragile marsupial populations.

Genotoxic biomarkers and histological changes in marine medaka (Oryzias melastigma) exposed to 17α-ethynylestradiol and 17β-trenbolone.

Endocrine-disrupting pollutants in marine environments have aroused great concern for their adverse effects on the reproduction of marine organisms. This study aimed to seek promising biomarkers for estrogenic/androgenic chemicals. First, two possible male-specific genes, SRY-box containing gene 9a2 (sox9a2) and gonadal soma-derived factor (gsdf), were cloned from marine medaka (Oryzias melastigma). Then the responses of sox9a2, gsdf, choriogenin (chgH and chgL), vitellogenin (vtg1 and vtg2), and cytochrome P450 aromatase (cyp19a and cyp19b) were investigated after exposure to 17α-ethynylestradiol (EE2) and 17β-trenbolone (TB) at 2, 10, and 50 ng/L. The results showed that gsdf was specifically expressed in the testes and easily induced in the ovaries after TB exposure, indicating that gsdf was a potential biomarker of environmental androgens. ChgL was a useful biomarker of weak estrogen pollution for its high sensitivity to low levels of EE2. In addition, both EE2 and TB exposure damaged gonadal structures and inhibited gonadal development.

The Effect of In-ovo Injection of Tomato Extract on Sex Differentiation and Gonadal Structure of Broiler Chicks and Their Performance

The Effect of In-ovo Injection of Tomato Extract on Sex Differentiation and Gonadal Structure of Broiler Chicks and Their Performance

Protective effects of zinc on rat sperm chromatin integrity involvement: DNA methylation, DNA fragmentation, ubiquitination and protamination after bleomycin etoposide and cis-platin treatment

Testicular cancer is one of the most common malignancy in young men, chemotherapy induced damage in cancerous cells as well as healthy tissue, and we decided to investigate recovery effect of zinc (Zn) on chemotherapy-induced complications in rat chromatin integrity and testicular histomorphometry. The male rats (n = 40) were treated with BEP at appropriate dose levels of BEP (0.75, 7.5, and 1.5 mg/kg) for 9 weeks, with or without Zn; testicular histology, sperm DNA methylation, ubiquitination, DNA fragmentation and protamination were further assessed through immunofluorescence. BEP treatment significantly increased ubiquitination, and DNA fragmentation, considerably reducing global DNA methylation and protamination (P < 0.001), resulting in degenerative changes in testicular structure. Zn restored normal DNA methylation, protamination and structure of male gonads, maintained spermatogonial stem cells, and significantly reduced the mean percentage of ubiquitination and sperm DNA fragmentation as compared with BEP group (P < 0.001). We found that supplementation of Zn following chemotherapy can improve chromatin integrity, testicular organization and spermatogenesis.

Development of gonads and evidence of protogyny in Spangled emperor (Lethrinus nebulosus) from the coastal waters off Negombo, Sri Lanka.

Gonad development and maturation of the spangled emperor Lethrinus nebulosus (Forsskål, 1775) inhabiting coastal waters off Negombo, Sri Lanka was investigated to understand the reproductive strategies. Sexual ontogeny was investigated using histological examinations of the gonads and changes in sex ratio with body size. Cellular characteristics and the most advanced germ cells presented in the gonads were considered for determining the sex and maturity stages. The transitional gonads were characterized by changes in internal gonad structure such as the appearance of spermatocyte and degenerated oocytes in the same developmental stage. Thick strands of stromal tissue within the lamellae and branched secondary strands were observed in transitional individuals. Increased blood vessels and sperm sinuses within the gonad wall were also an indications of sex transition. Therefore, L. nebulosus living in coastal waters off Negombo exhibited an early indication of protogynous hermaphroditism among adults. The sizes at 50% sexual maturity of males and females were estimated to be 29.5 cm and 39.5 cm respectively. A dramatic change in the sex ratio of the adult size classes suggested that female to male sex transition observed between 28.5- 40.4 cm body sizes. Sex ratios were 1.23: 0.46: 1 for female: transitional: males indicating slightly female-biased overall sex ratios. Female dominance in smaller size classes and male dominance in larger size classes were also evident Mean size at first capture recorded for L. nebulosus (19.6 cm) was well below the mean sizes of maturity for both male and female. Size-specific differences in sex ratios and reproductive potential indicate that conventional regulations that impose size limits for capture would not be very effective for the management of L. nebulosus.

Fertility Preservation Outcomes and Considerations in Transgender and Gender-Diverse Youth.

* Abbreviations: MAI — : medical affirming intervention TGD-AYA — : transgender and gender-diverse adolescents and young adults Transgender and gender-diverse adolescents and young adults (TGD-AYA) increasingly present to health care providers seeking medical affirming interventions (MAIs) to induce physiologic changes aligned with their gender identity. MAIs include gonadotropin-releasing hormone agonists to temporarily suppress puberty, testosterone to induce masculine characteristics among those assigned female at birth, and estrogen (often combined with an antiandrogenic agent) to induce feminine characteristics among those assigned male at birth. There is considerable concern that these MAIs impact gonadal structures and function, thereby decreasing future fertility potential.1 Little research has explored reversibility or thresholds (amount and/or duration) of MAIs in impacting TGD-AYA fertility. Therefore, multiple professional organizations recommend fertility counseling before MAI initiation.2–4 In this month’s issue of Pediatrics, Barnard et al5 provide the first study of semen cryopreservation outcomes among TGD-AYA assigned male at birth who assert a female gender identity. They conducted retrospective chart reviews on 11 TGD-AYA referred for fertility preservation over a nearly 4-year period. One patient did not provide a sample. The 8 samples obtained from patients before MAI initiation were all viable. One patient … Address correspondence to Jason Rafferty, MD, MPH, EdM, Department of Pediatrics, Thundermist Health Centers, 450 Clinton St, Woonsocket, RI 02895. E-mail: jason_rafferty{at}mail.harvard.edu

Gonad Histology, Proximate Composition and Growth Efficiency of Nile Tilapia Fed with Pawpaw (Carica papaya) Seeds Powder

The study was carried out to determine the effect of different inclusion levels of pawpaw seeds powder (PSP) on the proximate composition, growth and histological structure of Nile tilapia gonads. Nile tilapia were treated with pawpaw seeds powder at four levels at 0 g, 4 g, 8 g and 12 g PSP/kg feed for 60 days. The proximate composition of the carcass of the Nile tilapia showed that the 8 g PSP/kg feed treatment group had the highest values (mean ± SE) of Crude protein and ash (53.97 ± 0.094 and 20.05 ± 0.35) respectively. The highest body weight gain and specific growth rate was achieved at the 8 g PSP/kg treatment level but this treatment level showed the lowest feed conversion ratio. Histology of gonads of Nile tilapia treated with different levels of PSP revealed that ovaries and testes of 0 g PSP/kg feed were normal. Ovaries of the 4 g PSP/kg feed had degenerative stromas while testes had scanty spermatozoa. At 8 g PSP/kg feed, the ovaries showed increased atretic follicles and testes had degeneration of spermatozoa.Treatment with 12 g PSP/kg feed resulted in severe atretic follicles of the ovaries and deformation of seminiferous tubules and erosion of spermatozoa of the testes. The results of this study showed that pawpaw seeds powder can be used to control the breeding of Nile tilapia in production units.

Concentration-dependent effects of 17β-estradiol and bisphenol A on lipid deposition, inflammation and antioxidant response in male zebrafish (Danio rerio)

Environmental estrogenic compounds are important pollutants, which are widely distributed in natural water bodies. They produce various adverse effects on fish, but their concentration-dependent toxicities in fish metabolism and health are not fully understood. This study investigated the effects of 17β-estradiol (E2) and bisphenol A (BPA) at low and high concentrations on lipid deposition, inflammation and antioxidant response in male zebrafish. We measured fish growth parameters, gonad development, lipid contents and the activities of inflammatory and antioxidant enzymes, as well as their mRNA expressions. All E2 and BPA concentrations used increased body weight, damaged gonad structure and induced feminization in male zebrafish. The exposure of zebrafish to E2 and BPA promoted lipid accumulation by increasing total fat, liver triglycerides and free fatty acid contents, and also upregulated lipogenic genes expression, although they decreased total cholesterol content. Notably, zebrafish exposed to low concentrations of E2 (200 ng/L) and BPA (100 μg/L) had higher lipid synthesis and deposition compared to high concentrations (2000 ng/L and 2000 μg/L, respectively). However, the high concentrations of E2 and BPA increased inflammation and antioxidant response. Furthermore, BPA caused greater damage to fish gonad development and more severe lipid peroxidation compared to E2. Overall, the results suggest that the toxic effects of E2 and BPA on zebrafish are concentration-dependent such that, the relative low concentrations used induced lipid deposition, whereas the high ones caused adverse effects on inflammation and antioxidant response.

Role for androgens in determination of ovarian fate in the common snapping turtle, Chelydra serpentina

Sex steroids are involved in sex determination in almost all vertebrates, including species with temperature-dependent sex determination (TSD). It is well established that aromatase and estrogens are involved in ovary determination in TSD species. In contrast, the role of non-aromatizable androgens in TSD is less clear. In this study, we used dihydrotestosterone (DHT) and an antagonist of the mammalian androgen receptor (flutamide) to examine the impact of androgens on sex determination in the snapping turtle. We incubated eggs at a male-producing temperature and treated embryos with drug delivery vehicle (5 L ethanol), DHT in vehicle, or flutamide in vehicle during the sex-determining period. We then measured expression of markers for ovarian and testicular development and genes involved in steroidogenesis. A subset of embryos and hatchlings were collected for histological analysis of gonad differentiation and sex determination. DHT and flutamide both induced ovarian development: 100% of vehicle-treated hatchlings had testes, while 60% of DHT-treated and 32% flutamide-treated hatchlings had ovaries. DHT and flutamide treatments also had feminizing effects on gene expression patterns and the structure of embryonic gonads. DHT treatment increased expression of FoxL2, androgen receptor, aromatase and several steroidogenic genes. Flutamide produced a similar, but weaker, pattern of gene expression. Genes involved in testis development (Sox9 and Amh) were influenced by flutamide treatment. Our findings support the hypothesis that androgens and the androgen receptor are involved in ovary determination in the common snapping turtle.

Biological Characteristics of Dendrochirus zebra (Cuvier, 1829) (Scorpaeniformes: Scorpaenidae) from Nha Trang Bay, South China Sea

The biological characteristics of the zebra turkeyfish Dendrochirus zebra (Cuvier, 1829) from Nha Trang Bay, South China Sea, including the total length (TL) to body weight (W) relationship, body size at first sexual maturity, otolith growth, gonad structure, and ultrastructure of the envelopes of ovulated oocytes, were studied. The TL–W relationship is different in the males and females, which is connected with their different growth rates. The largest fish are mostly males. The females differ from males in three from six otolith (sagitta) shape indices and in otolith contours described based on elliptic Fourier analysis. Mature spermatozoa are observed in spermiducts of males larger than 106 mm TL, and 50% of the females reach sexual maturity by 113 mm TL. A positive allometry was found between linear growth of the urinary bladder and body length of the males. The envelope of an ovulated oocyte consists of a three-layered zona radiatа 0.6–0.9 μm in width and a weakly expressed chorion approximately 0.2 μm in width. The features of D. zebra biology are discussed based on the published data for other representatives of the suborder Scorpaenoidei and subfamily Pteroinae.

Matrix metalloproteinase-dependent regulation of extracellular matrix shapes the structure of sexually differentiating mouse gonads

The extracellular matrix (ECM) proteins play an important role in the establishment of the sex-dependent structure of developing gonads. The matrix metalloproteinases (MMPs) are the major players in the regulation of ECM. Our hypothesis was that the MMPs-dependent regulation of EMC is crucial for the establishment of the correct, either testis or ovary, structure of developing gonad. We cultured developing mouse gonads in vitro in the presence of the MMPs inhibitors (α-2-macroglobulin, leupeptin, phosphoramidon) or the MMPs activator, APMA (4-aminophenylmercuric acetate). These inhibitors and activator inhibit/activate, to a different degree, matrix metalloproteinases, but the exact mechanism of inhibition/activation remains unknown. We found that the MMP inhibitors increased accumulation of ECM in the developing gonads. The α-2-macroglobulin had the weakest, and the phosphoramidon the strongest effect on the ECM and the structure of the gonads. The α-2-macroglobulin caused a slight increase of ECM and did not disrupt the gonad structure. Leupeptin led to the strong accumulation of ECM, resulted in the formation of the structures resembling testis cords in both testes and ovaries, and caused increase of apoptosis and complete loss of germ cells. Phosphoramidon caused the strongest accumulation of ECM, which separated individual cells and completely prevented intercellular adhesion both in the testes and in the ovaries. As a result of aberrant morphology, the sex of the phosphoramidon-treated gonads was morphologically unrecognizable. The APMA - the activator of MMP caused ECM loss, which led to the loss of cell adhesion, cell dispersion and an aberrant morphology of the gonads. These results indicate that the ECM accumulation is MMPs-dependent and that the correct amount and distribution of ECM during gonad development plays a key role in the formation of the gonad structure.