Infestation of the squat lobster Munida gregaria (Anomura: Galatheidae) by Pseudione galacanthae (Isopoda: Bopyridae) in San Jorge Gulf, Argentina

2010 ◽  
Vol 91 (8) ◽  
pp. 1681-1688 ◽  
Author(s):  
Martín Varisco ◽  
Julio Vinuesa

We estimated the prevalence of the bopyrid Pseudione galacanthae parasitizing the population of the squat lobster Munida gregaria in San Jorge Gulf and analysed some aspects concerning the effect of the parasite on host reproductive potential. The relationship between the development stages of the parasite and the host size was also analysed. The squat lobsters were caught as by-catch in the coastal area of the gulf from vessels operating in the fisheries of hake Merluccius hubbsi, southern king crab Lithodes santolla and Argentine red shrimp Pleoticus muelleri. The samples were collected between October 1997 and June 2009. In the laboratory, squat lobsters were sexed and the length of their carapace was measured. In males, the length of the right cheliped was recorded and gonadal development was examined. In females, the size and number of carried eggs were determined and the length of the pleopods III, IV and V were measured. All squat lobsters parasitized exhibit a gross bulge in the right side of carapace. Prevalence ranged between 0 and 1.43% (N = 21,519). No significant differences in prevalence were found for sexes, depths and seasons. The prevalence was higher for the size interval 7–10 mm CL (0.79%) than for the rest of the intervals. Parasitism had no effect on the secondary sex characters. Parasitized males displayed gonad development. There was no difference in prevalence between ovigerous and non-ovigerous squat-lobster females. Parasitized females had smaller eggs than non-parasitized ones, but their fecundity was similar. The linear relationship between the parasite and host sizes and the presence of larvae and immature stages of P. galacanthae in small-sized squat lobsters suggest that the host is infected early in its development. The low prevalence could be related to oceanographic conditions which favour larval dispersal of the parasite and host. The infestation by P. galacanthae has little impact on the M. gregaria population, mostly due to the low prevalences of infestation and the minor impact in reproductive function.

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Tridjoko Tridjoko

This study aimed to determine the effect of LHRH-a hormone implantation on gonadal development of humpback grouper, Cromileptes altivelis 2nd generation (F-2). Individuals used were 20 female grouper fish with weight range of 600-800 gram/fish and total length range of 28.0-30.0 cm. The treatment used 5 fish each with tagging. Grouper fishes were stocked into the 75 m3 circular concrete tank. Hormone of LHRH-a with dosage of 50 μg/kg body weight was used as implant treatment of (A) 1 time,, (B) 2 times, (C) 3 times, and (D) without implant. The results showed that implantation of LHRH-a hormone were significantly stimulate gonad development of humpback grouper second generation (F-2). Treatment of 3 times implant every month showed the best results produced  oocyte diameter up to 480 μm, while the control of oocyte diameter only reached <400 μm. Keywords: LHRH-a hormone, implantation, Humpback grouper, gonad development


2019 ◽  
Author(s):  
Kjetil Hodne ◽  
Romain Fontaine ◽  
Eirill Ager-Wick ◽  
Finn-Arne Weltzien

ABSTRACTReproductive function in vertebrates is stimulated by gonadotropin-releasing hormone (GnRH) that controls the synthesis and release of the two pituitary gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). FSH and LH, which regulates different stages of gonadal development, are produced by two different cell types in the fish pituitary, in contrast to mammals and birds, thus allowing the investigation of their differential regulation. In the present work, we show by fluorescentin situhybridization that Lh cells in adult female medaka express Gnrh receptors, whereas Fsh cells do not. This is confirmed by patch clamp recordings and cytosolic Ca2+measurements on dispersed pituitary cells, where Lh cells, but not Fsh cells, respond to Gnrh1 by increased action potential frequencies and cytosolic Ca2+levels. In contrast, both Fsh and Lh cells are able to respond electrically and by elevating the cytosolic Ca2+levels to Gnrh1 in brain-pituitary tissue slices. Using Ca2+uncaging in combination with patch clamp recordings and cytosolic Ca2+measurements, we show that Fsh and Lh cells form homo- and heterotypic networks in the pituitary. Taken together, these results show that the effects of Gnrh1 on Fsh release in adult female medaka is indirect, likely mediated via Lh cells.


2020 ◽  
Author(s):  
Rui Wang ◽  
Luting Wen ◽  
Huawei Ma ◽  
Huizan Yang ◽  
Min Lv ◽  
...  

Abstract Background: Gonadotropin releasing hormone (GnRH) plays an important role in the regulation of vertebrate reproduction. Studies have shown that immunization against GnRHa can induce sexually sterile tilapia. To explore the mechanism behind this, in this study, RNA-seq and data-independent acquisition (DIA) techniques were used to study the transcriptome and proteome of the gonad of tilapia immunized with GnRHa. Results : 644 differentially expressed genes (80 upregulated and 564 downregulated) and 1150 differentially expressed proteins (351 upregulated and 799 downregulated) were identified. There were 209 genes with consistent differential expression patterns in the transcriptomic and proteomic analyses, of which 9 were upregulated and 200 downregulated, indicating that the gonad gene expression was inhibited by GnRHa immunization. The downregulated genes were particularly involved in the functions of single-organism process, binding, cellular process, metabolic process and catalytic activity, and associated with the pathways including ECM–receptor interaction, focal adhesion, cardiac muscle contraction and oxidative phosphorylation. The expression of six differentially expressed genes involved in the GnRH signaling pathway was all downregulated. In addition, several important functional genes related to gonadal development after GnRHa immunization were screened. Conclusions: This study confirmed the expression of corresponding genes was affected by GnRHa on the gonad development in tilapia at the molecular level, and laid a foundation for elucidating the mechanism of GnRHa immunization.


Zootaxa ◽  
2021 ◽  
Vol 4996 (2) ◽  
pp. 363-373
Author(s):  
EMANUEL PEREIRA ◽  
BRENDA LÍA DOTI ◽  
DANIEL ROCCATAGLIATA

A new bopyrid, Pseudione chiesai n. sp., is herein described based on an ovigerous female and an adult male found in the right branchial chamber on a specimen of Munida spinosa Henderson, 1885. This parasite was collected in the Mar del Plata submarine canyon at 819 m depth during the expedition “Talud Continental I” carried out by the Argentine RV Puerto Deseado in 2012. P. chiesai n. sp. belongs to the Pseudione “crénelés” group sensu Bourdon (1972, 1976), which currently contains seven species, all of which have galatheoid crabs as hosts. P. chiesai n. sp. can be separated from the other species in the Pseudione “crénelés” group by the following combination of characters: (1) both sides of the body convex, (2) frontal lamina with a few, shallow indentations, (3) coxal plates 1–4 and tergal projections 1–4 with distinct irregular margins, mainly on the right side, (4) pereomeres 5–7 with single/branched lateral digitations, (5) maxilliped palp well-developed and setose, and (6) pleon with lateral plates 1–5 distally rounded and directed laterally. The taxonomic position of this new species is briefly discussed.  


2020 ◽  
Vol 8 (5) ◽  
pp. 399-403
Author(s):  
Wu Jiang ◽  
Qiao-Qi Sui ◽  
Wen-Liang Li ◽  
Chuan-Feng Ke ◽  
Yi-Hong Ling ◽  
...  

Abstract Background Although universal testing for mismatch repair deficiency (dMMR) has been recommended to all colorectal cancer (CRC) patients, related evidence for the Chinese population is lacking. Here, we investigated the prevalence and clinicopathological features of dMMR patients in a large Chinese CRC cohort. Methods We included 7,373 CRC patients treated at four Chinese medical centers between August 2010 and September 2016. Patients’ baseline characteristics and pathological features were recorded. The clinicopathological features were compared between patients with MLH1/PMS2 deficiency (dMLH1/PMS2) and MSH2/MSH6 deficiency (dMSH2/MSH6). Results Among the investigated patients, 654 (8.9%) were identified with dMMR CRCs and, of them, 401 (61.3%) were males, with a median age of 55 years (range, 22–87 years); 355 (54.3%) had stage II CRC based on American Joint Committee on Cancer 8th edition. The prevalence of the dMLH1/PMS2 group and the dMSH2/MSH6 group were 51.5% (337/654) and 25.1% (164/654), respectively. Compared with dMSH2/MSH6 patients, those with dMLH1/PMS2 were older (57 vs 52 years, P &lt; 0.001), more likely to be female (45.7% vs 31.5%, P = 0.004), prone to having tumors located in the right-hand side of the colon (59.0% vs 47.6%, P = 0.015), and less likely to have a family history of tumors (29.7% vs 43.3%, P = 0.003). Conclusions The prevalence of dMMR in Chinese CRC patients was low, especially in the dMLH1/PMS2 group. The clinicopathological features were different between dMMR subgroups.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1103
Author(s):  
Furong Tang ◽  
Nainoa Richardson ◽  
Audrey Albina ◽  
Marie-Christine Chaboissier ◽  
Aitana Perea-Gomez

The transcription factors SRY and SOX9 and RSPO1/WNT4/β-Catenin signaling act as antagonistic pathways to drive testis and ovary development respectively, from a common gonadal primordium in mouse embryos. In this work, we took advantage of a double knockout mouse model to study gonadal development when Sox9 and Wnt4 are both mutated. We show that the XX gonad mutant for Wnt4 or for both Wnt4 and Sox9 develop as ovotestes, demonstrating that ectopic SOX9 function is not required for the partial female-to-male sex reversal caused by a Wnt4 mutation. Sox9 deletion in XY gonads leads to ovarian development accompanied by ectopic WNT/β-catenin signaling. In XY Sox9 mutant gonads, SRY-positive supporting precursors adopt a female-like identity and develop as pre-granulosa-like cells. This phenotype cannot be fully prevented by the deletion of Wnt4 or Rspo1, indicating that SOX9 is required for the early determination of the male supporting cell identity independently of repressing RSPO1/WNT4/β-Catenin signaling. However, in XY Sox9 Wnt4 double mutant gonads, pre-granulosa cells are not maintained, as they prematurely differentiate as mature granulosa cells and then trans-differentiate into Sertoli-like cells. Together, our results reveal the dynamics of the specific and independent actions of SOX9 and WNT4 during gonadal differentiation: SOX9 is essential in the testis for early specification of male-supporting cells whereas WNT4 functions in the ovary to maintain female-supporting cell identity and inhibit male-specific vascular and steroidogenic cell differentiation.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Mary K. Samplaski ◽  
Trustin Domes ◽  
Keith A. Jarvi

Introduction. Chlamydia trachomatis is an established cause of tubal factor infertility; however its role in male fertility is not as clear. We sought to determine the prevalence of Chlamydia in infertile men and evaluate its impact on male reproductive potential. Materials and Methods. We compared the incidence of Chlamydia in our infertile male population with that reported in the literature. We then reviewed the impact of Chlamydia infection on male fertility. Results. The incidence of Chlamydia infection in our population of infertile men was 0.3%. There is considerable variability in the reported incidence, likely due to variation in the population studied, and detection technique. The optimal testing method and sample are presently unclear. The effect of Chlamydia on male reproductive function is also variable in the literature, but appears to be relatively minimal and may be related primarily to sperm DNA fragmentation or female partner transmission. Conclusions. The prevalence of Chlamydia in the infertile male population is low and routine testing is not supported by the literature. For high-risk infertile men, nucleic acid testing of urine +/− semen is the most sensitive method to detect Chlamydia. A validated testing system for semen needs to be developed, so that a standardized methodology can be recommended. In this way the full implications of Chlamydia on male fertility can be elucidated.


2017 ◽  
Vol 63 (No. 1) ◽  
pp. 1-10 ◽  
Author(s):  
Z. Linhartová ◽  
M. Havelka ◽  
M. Pšenička ◽  
M. Flajšhans

Gonad development in fish is generally assumed to be negatively influenced by interspecific hybridization, resulting in sterility or sub-sterility. However, this is not the case in sturgeons (Acipenseridae), in which fertile hybrids are common. In the present study, we investigated gonad development in several sturgeon interspecific hybrids and purebred species. Six interspecific hybrid groups and three purebred groups were analyzed including 20 hybrid specimens with even ploidy, 40 specimens having odd ploidy levels, and 30 purebred specimens. Hybrids of species with the same ploidy (even ploidy – 2n, 4n) exhibited normally developed gonads similar to those seen in purebred specimens. In contrast, hybrids of species differing in ploidy (odd ploidy – 3n) did not display fully developed gonads. Ovaries were composed of oocytes or nests of differentiating oocytes that ceased development in early stages of meiosis (pachytene to zygotene) with a higher content of adipose and apoptotic tissue. Testes contained single spermatogonia along with Sertoli cells and spaces lacking germ cells. The obtained results showed that gonad development was influenced by genetic origin and ploidy of the sturgeon hybrids and were consistent with full fertility of hybrids with even ploidy. Sterility of females, but possibly limited fertility of males, is suggested for hybrids with odd ploidy.


1998 ◽  
Vol 76 (7) ◽  
pp. 1209-1216 ◽  
Author(s):  
Jacqueline Faulkner ◽  
Lena N Measures ◽  
Fred G Whoriskey

Seventy-eight harbour porpoises, Phocoena phocoena (33 females, 45 males), were obtained in summer (June-September) as incidental by-catch from the cod fishery in the Gulf of St. Lawrence and examined for the presence of cranial sinus nematodes. Stenurus minor (Kühn, 1829) Baylis and Daubney, 1925 were present in the cranial sinuses of all adult porpoises (>1 year old, N = 66, mean intensity = 2362, range = 87-8920) and absent in all young of the year (<1 year old, N = 12). Only fifth-stage worms were observed and these were equally distributed between the right and left sides of the skull (mean intensity = 1158 and 1213 in the left and right side, respectively). However, S. minor were approximately twice as numerous in the frontal sinuses as in the ear sinuses. Mean intensities of S. minor were similar among all infected porpoises. Parasite load had no apparent effect on porpoise body condition (measured as percent blubber mass of the carcass). No gross lesions associated with the presence of numerous S. minor in the cranial sinuses were observed. There was an inverse relationship between the intensity of S. minor infection and mean worm length, which is suggestive of a "crowding effect." Mean worm length was 17.8 ± 0.2 mm in lightly infected porpoises and 16.1 ± 0.2 mm in heavily infected animals.


Crustaceana ◽  
2018 ◽  
Vol 91 (3) ◽  
pp. 363-373 ◽  
Author(s):  
Dong Dong ◽  
Xinzheng Li

Squat lobsters are prevalent in chemosynthetic environments but have been insufficiently studied in mud volcano habitats. An abyssal species,Munidopsis taiwanicaOsawa, Lin & Chan, 2008 was recently collected in a mud volcano field in the Mariana Trench at a depth greater than 5000 m, which represents a new distributional record. Its diagnostic characters are presented in this study. In-situ observation suggested thatM. taiwanicawas closely associated with this chemosynthetic environment and probably exhibited camouflage behaviour by attaching seafloor sediments onto its body.Munidopsis taiwanicais the first confirmed species of squat lobster found in the mud volcano environment, and currently represents the deepest record (5491 m) of squat lobsters in the world.


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