Genetic and Molecular Analysis of hyperplastic discs, a Gene Whose Product Is Required for Regulation of Cell Proliferation in Drosophila melanogaster Imaginal Discs and Germ Cells

1994 ◽  
Vol 165 (2) ◽  
pp. 507-526 ◽  
Author(s):  
Elizabeth Mansfield ◽  
Evelyn Hersperger ◽  
Joseph Biggs ◽  
Allen Shearn
1999 ◽  
Vol 112 (17) ◽  
pp. 2875-2884
Author(s):  
B. Alsina ◽  
M. Corominas ◽  
M.J. Berry ◽  
J. Baguna ◽  
F. Serras

The patufet gene encodes the Drosophila melanogaster homologue of selenophosphate synthetase, an enzyme required for selenoprotein synthesis, and appears to have a role in cell proliferation. In this paper we analyse the expression pattern of patufet during the development of imaginal discs and brain as well as the function of this gene in relation to cell proliferation. Wild-type organisms showed a highly dynamic pattern of ptuf mRNA expression during larval and pupal development. Co-localization analysis of ptuf mRNA expression and BrdU incorporation showed high levels of ptuf mRNA in dividing cells and low or undetectable levels in non-dividing cells. In addition, [(75)Se] incorporation revealed a major selenoprotein band of 42 kDa. Mutant organisms showed no selenoprotein synthesis, lower levels of cell proliferation, a higher proportion of cells arrested in G(2) as seen by cyclin B labeling and increased levels of reactive oxygen species (ROS). Because most selenoproteins identified so far are antioxidants, the role of ptuf in cell proliferation through the control of the cellular redox balance is discussed.


2021 ◽  
pp. 1-14
Author(s):  
Yuanyuan Li ◽  
Jinbo Li ◽  
Man Cai ◽  
Zhanfen Qin

The knowledge of testis development in amphibians relative to amniotes remains limited. Here, we used Xenopus laevis to investigate the process of testis cord development. Morphological observations revealed the presence of segmental gonomeres consisting of medullary knots in male gonads at stages 52–53, with no distinct gonomeres in female gonads. Further observations showed that cell proliferation occurs at specific sites along the anterior-posterior axis of the future testis at stage 50, which contributes to the formation of medullary knots. At stage 53, adjacent gonomeres become close to each other, resulting in fusion; then (pre-)Sertoli cells aggregate and form primitive testis cords, which ultimately become testis cords when germ cells are present inside. The process of testis cord formation in X. laevis appears to be more complex than in amniotes. Strikingly, steroidogenic cells appear earlier than (pre-)Sertoli cells in differentiating testes of X. laevis, which differs from earlier differentiation of (pre-)Sertoli cells in amniotes. Importantly, we found that the mesonephros is connected to the testis gonomere at a specific site at early larval stages and that these connections become efferent ducts after metamorphosis, which challenges the previous concept that the mesonephric side and the gonadal side initially develop in isolation and then connect to each other in amphibians and amniotes.


Endocrinology ◽  
2007 ◽  
Vol 149 (4) ◽  
pp. 1813-1819 ◽  
Author(s):  
Eri Shiraishi ◽  
Norifumi Yoshinaga ◽  
Takeshi Miura ◽  
Hayato Yokoi ◽  
Yuko Wakamatsu ◽  
...  

Müllerian inhibiting substance (MIS) is a glycoprotein belonging to the TGF-β superfamily. In mammals, MIS is responsible for the regression of Müllerian ducts in the male fetus. However, the role of MIS in gonadal sex differentiation of teleost fish, which have no Müllerian ducts, has yet to be clarified. In the present study, we examined the expression pattern of mis and mis type 2 receptor (misr2) mRNAs and the function of MIS signaling in early gonadal differentiation in medaka (teleost, Oryzias latipes). In situ hybridization showed that both mis and misr2 mRNAs were expressed in the somatic cells surrounding the germ cells of both sexes during early sex differentiation. Loss-of-function of either MIS or MIS type II receptor (MISRII) in medaka resulted in suppression of germ cell proliferation during sex differentiation. These results were supported by cell proliferation assay using 5-bromo-2′-deoxyuridine labeling analysis. Treatment of tissue fragments containing germ cells with recombinant eel MIS significantly induced germ cell proliferation in both sexes compared with the untreated control. On the other hand, culture of tissue fragments from the MIS- or MISRII-defective embryos inhibited proliferation of germ cells in both sexes. Moreover, treatment with recombinant eel MIS in the MIS-defective embryos dose-dependently increased germ cell number in both sexes, whereas in the MISRII-defective embryos, it did not permit proliferation of germ cells. These results suggest that in medaka, MIS indirectly stimulates germ cell proliferation through MISRII, expressed in the somatic cells immediately after they reach the gonadal primordium.


Gene ◽  
2000 ◽  
Vol 246 (1-2) ◽  
pp. 157-167 ◽  
Author(s):  
Thorsten Burmester ◽  
Mátyás Mink ◽  
Margit Pál ◽  
Zsolt Lászlóffy ◽  
Jean-Antoine Lepesant ◽  
...  

2008 ◽  
Vol 321 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Bradley C. Stieper ◽  
Mania Kupershtok ◽  
Michael V. Driscoll ◽  
Alexander W. Shingleton

Development ◽  
1993 ◽  
Vol 118 (4) ◽  
pp. 1291-1301 ◽  
Author(s):  
M. Boedigheimer ◽  
A. Laughon

The expanded gene was first identified by a spontaneous mutation that causes broad wings. We have identified an enhancer-trap insertion within expanded and used it to generate additional mutations, including one null allele. expanded is an essential gene, necessary for proper growth control of imaginal discs and, when mutant, causes either hyperplasia or degeneration depending on the disc. Wing overgrowth in expanded hypermorphs is limited to specific regions along the anterior-posterior and dorsal-ventral axis. expanded encodes a novel 1429 amino acid protein that is localized to the apical surface of disc cells and contains three potential SH3-binding sites. Together, these observations suggest that the Expanded protein engages in protein-protein interactions regulating cell proliferation in discs.


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