scholarly journals The stage of ovarian development affects organ expression of vitellogenin as well as the morphometry and ultrastructure of germ cells in the freshwater prawn Macrobrachium amazonicum (Heller, 1862)

2012 ◽  
Vol 78 (5) ◽  
pp. 981-990 ◽  
Author(s):  
M.A.P. Ferreira ◽  
B.M. Resende ◽  
M.Y.S. Lima ◽  
S.S.D. Santos ◽  
R.M. Rocha
2019 ◽  
Vol 278 ◽  
pp. 46-56 ◽  
Author(s):  
Gicelle M.F. Silva ◽  
Yanne A. Mendes ◽  
Ivana K.S. Viana ◽  
Liziane A.B. Gonçalves ◽  
Renata S. Oliveira ◽  
...  

2019 ◽  
Vol 109 ◽  
Author(s):  
Emerson Ventura ◽  
Allysson Winick-Silva ◽  
Renata A. Shinozaki-Mendes

ABSTRACT Macrobrachium amazonicum (Heller, 1862) is the most important species for aquaculture native to South America. This study evaluates the phenotypic plasticity of females of Macrobrachium amazonicum with respect to the gonadal development, and determines the spawning type. Our study consisted of macro and microscopic analysis of the reproductive tract. Ovaries exhibited the following reproductive cells in developmental sequence: oogonia (OO) - mean diameter and standard deviation of 25.4 ± 6.5 μm; previtellogenic oocyte (PVO) - 61.7 ± 10.7 μm, vitellogenic oocyte (VO) - 113.9 ± 24.5 μm; and mature oocyte (MO) - 308.7 ± 56.3 μm. Ovaries increased in volume due to vitellogenesis and changing of basophilic to acidophilic composition. Follicular cells, atresic oocytes and postovulatory follicles were also analyzed. By combining macro and microscopic analysis, the ovaries of M. amazonicum were classified into six stages: Immature, In maturation, Mature, Spawned in maturation, Spawned and Resting. The ovarian development of M. amazonicum followed a standard pattern even among different populations. Considering our results and the evidence in literature, we conclude that spawning for this species is parceled or multiple, that is, synchronous in more than two groups (clutches of oocytes). Such observations provide basis for further studies addressing sustainable management strategies for species conservation and contribute to elucidate the biology of their specimens.


2020 ◽  
Vol 46 (3) ◽  
pp. 1-8
Author(s):  
Lubia Maciel MIRANDA ◽  
◽  
Larissa Rosa RODRIGUES ◽  
João Alberto Farinelli PANTALEÃO ◽  
Luciana Segura de ANDRADE ◽  
...  

The migratory behavior of females of the freshwater prawn Macrobrachium amazonicum (Heller, 1862) can indicate a strategy that optimizes the population establishment. With this idea in mind, we evaluated the reproductive biology of M. amazonicum, hypothesizing that females were evenly distributed downstream of Hydroelectric Dam. Specimens were collected monthly for one year, from six sites of Rio Grande river. The specimens were sexed and measured (carapace length; CL). A total of 14,697 adults were captured, 2,864 males (AM), 11,082 non-breeding females (AF) and 751 breeding females (BF). The smallest BF had 3.8 mm CL. The distribution of demographic groups was assessed by a Principal Component Analysis (PCA), which explained 95.16% of the distribution over the collection sites. Breeding females were more abundant in the sites closest to the dam. This result can be explained by rainfall, which varied significantly throughout the year. As the breeding females migrated upstream toward the dam and were more abundant there, our hypothesis of homogeneous distribution was rejected. This behavior probably optimizes larval dispersion. The reproduction was continuous with peaks in the period preceding the maximum rainfall.


2002 ◽  
Vol 87 (2) ◽  
pp. 890-897 ◽  
Author(s):  
Richard A. Anderson ◽  
Lynne L. L. Robinson ◽  
Julie Brooks ◽  
Norah Spears

Mammalian ovarian development is characterized by a sequential pattern of mitotic proliferation of oogonia, initiation then arrest of meiosis, and primordial follicle formation. The factors regulating these processes are poorly understood. The neurotropins are survival and differentiation factors in the nervous system, acting via high affinity receptors of the trk protooncogene family and the low affinity p75 nerve growth factor receptor, and have also been described in the rodent ovary, where changes in NT4/TrkB gene expression have been detected at the time of primordial follicle formation. There are no data on neurotropin expression in the normal human ovary. We have investigated the expression and localization of neurotropins and their receptors in the midtrimester human fetal ovary (13–21 wk gestation). Expression of mRNA for neurotropins and their receptors was detected by RT-PCR. Clusters of oogonia were found to be the predominant site of NT4 mRNA expression using in situ hybridization. However, at later gestations granulosa cells of primordial follicles showed increased expression, with lesser expression in the enclosed oocytes. NT4 protein was also localized to the granulosa cells by immunohistochemistry and at earlier developmental stages to epithelioid cells, which were mingled with clusters of oogonia not expressing NT4. TrkB receptor protein was localized by immunohistochemistry to germ cells at all gestations examined. The p75 nerve growth factor receptor protein was exclusively expressed in the ovarian stroma. These data demonstrate the expression of neurotropins and their receptors within the human fetal ovary. Developmental changes in the pattern of expression of NT4 around the time of primordial follicle formation suggest that neurotropins may be involved in signaling between somatic cells and germ cells at this crucial stage of ovarian development.


Sign in / Sign up

Export Citation Format

Share Document