233. A role for activin/inhibin in mouse gonocyte relocation and proliferation

2008 ◽  
Vol 20 (9) ◽  
pp. 33
Author(s):  
L. Tubino ◽  
B. Barakat ◽  
S. Prahbu ◽  
S. Meachem ◽  
A. Nagaraja ◽  
...  

Gonocytes in the testis resume proliferation after birth and relocate to contact the basement membrane of the seminiferous cords where they become spermatogonia. A previous in vitro study indicated that activin can increase gonocyte numbers on day 3 postpartum (dpp) rat testis, while the activin antagonist, follistatin, together with FSH, increased the number of spermatogonia (Meehan et al. 2000). The aim of this study was to understand how FSH, activin and inhibin, a potent activin antagonist, interact to influence gonocyte proliferation and relocation in the newborn mouse testis using in vivo and in vitro approaches. Two mouse models were analysed, the inhibin α knock out (inh a −/−) mouse and the InhbaBK mouse. The Inh a −/− mouse lacks inhibin, and thus activin acts unopposed by its most potent antagonist (Matzuk et al. 1992). The InhbaBK mouse has the Inhbb allele inserted into the Inhba locus, thus directing the expression of the less bioactive activin βB, in the spatiotemporal pattern of activin βA (Brown et al. 2000). In addition, an in vitro model was developed in which 1dpp wild type testis fragments were cultured in hanging drops for 24 h with the addition of combinations of activin, inhibin and FSH. Gonocyte proliferation in inh a −/− was assessed using proliferating cell nuclear antigen (PCNA). A significant increase in germ cell proliferation and relocation to the basement membrane was measured in 0dpp inh a −/−, while no difference was observed at 4dpp. The opposite was observed in InhbaBK mice, with reduced gonocyte migration in mutant animals at 0dpp. In vitro, inhibin seemed to inhibit proliferation and reduce the percentage of relocated gonocytes while FSH showed a tendency for the opposite effect on gonocyte migration. These findings show that inhibin levels affect germ cell development during early postnatal development in mouse testis influencing both cell maturation and proliferation. (1) Meehan T, Schlatt S, O'Bryan MK, de Kretser DM, Loveland KL. Regulation of germ cell and Sertoli cell development by activin, follistatin, and FSH. Dev Biol. 2000 Apr 15;220(2):225–37. (2) Matzuk MM, Finegold MJ, Su JG, Hsueh AJ, Bradley A. Alpha-inhibin is a tumour-suppressor gene with gonadal specificity in mice. Nature. 1992 Nov 26;360(6402):313–9. (3) Brown CW, Houston-Hawkins DE, Woodruff TK, Matzuk MM. Insertion of Inhbb into the Inhba locus rescues the Inhba null phenotype and reveals new activin functions. Nat Genet. 2000 Aug;25(4):453–7.

2016 ◽  
Vol 7 (1) ◽  
pp. 247-255 ◽  
Author(s):  
Nicholas R. Y. Ho ◽  
Abul R. Usmani ◽  
Yan Yin ◽  
Liang Ma ◽  
Donald F. Conrad

2021 ◽  
Author(s):  
Lacy Barton ◽  
Justina Sanny ◽  
Emily P Dawson ◽  
Marcela Nouzova ◽  
Fernando G Noriega ◽  
...  

Germ cells are essential to sexual reproduction. Across the animal kingdom, extracellular isoprenoids, such as retinoic acids (RAs) in vertebrates and juvenile hormones (JHs) in insects, impact the germline lifecycle from meiosis to gametogenesis. Emerging evidence suggests that these bioactive isoprenoids also influence embryonic reproductive development, though the precise functions remain unclear. Here, we investigated the specific molecular pathways by which JHs regulates embryonic germ cell development in Drosophila. With a newly generated in vivo reporter, we find that JH signaling is active in the vicinity of germ cells as they migrate to colonize the somatic gonad. Through a combination of in vivo and in vitro assays, we find that JHs are both necessary and sufficient for primordial germ cell migration through mechanisms independent of canonical nuclear receptor-mediated transcription. These findings reveal that JH is present during Drosophila embryogenesis and that bioactive isoprenoids impact germ cell development earlier than previously appreciated. Interestingly, we find that like JH in Drosophila, RA is sufficient for murine germ cell migration in vitro, suggesting that the impact of bioactive isoprenoids on embryonic germ cell development may be broadly conserved.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomoko Nakanishi ◽  
Aya Maekawa ◽  
Mariko Suzuki ◽  
Hirotaka Tabata ◽  
Kumiko Sato ◽  
...  

AbstractSimultaneous expression of multiplex guide RNAs (gRNAs) is valuable for knockout of multiple genes and also for effective disruption of a gene by introducing multiple deletions. We developed a method of Tetraplex-guide Tandem for construction of cosmids containing four and eight multiplex gRNA-expressing units in one step utilizing lambda in vitro packaging. Using this method, we produced an adenovirus vector (AdV) containing four multiplex-gRNA units for two double-nicking sets. Unexpectedly, the AdV could stably be amplified to the scale sufficient for animal experiments with no detectable lack of the multiplex units. When the AdV containing gRNAs targeting the H2-Aa gene and an AdV expressing Cas9 nickase were mixed and doubly infected to mouse embryonic fibroblast cells, deletions were observed in more than 80% of the target gene even using double-nicking strategy. Indels were also detected in about 20% of the target gene at two sites in newborn mouse liver cells by intravenous injection. Interestingly, when one double-nicking site was disrupted, the other was simultaneously disrupted, implying that two genes in the same cell may simultaneously be disrupted in the AdV system. The AdVs expressing four multiplex gRNAs could offer simultaneous knockout of four genes or two genes by double-nicking cleavages with low off-target effect.


2002 ◽  
Vol 9 (2) ◽  
pp. 86-95 ◽  
Author(s):  
Denise A. Kaminski ◽  
John J. Letterio ◽  
Peter D. Burrows

Transforming growth factor β (TGFβ) can inhibit thein vitroproliferation, survival and differentiation of B cell progenitors, mature B lymphocytes and plasma cells. Here we demonstrate unexpected, age-dependent reductions in the bone marrow (BM) B cell progenitors and immature B cells in TGFβ1-/-mice. To evaluate TGFβ responsiveness during normal B lineage development, cells were cultured in interleukin 7 (IL7)±TGFβ. Picomolar doses of TGFβ1 reduced pro-B cell recoveries at every timepoint. By contrast, the pre-B cells were initially reduced in number, but subsequently increased compared to IL7 alone, resulting in a 4-fold increase in the growth rate for the pre-B cell population. Analysis of purified BM sub-populations indicated that pro-B cells and the earliest BP1-pre-B cells were sensitive to the inhibitory effects of TGFβ1. However, the large BP1+pre-B cells, although initially reduced, were increased in number at days 5 and 7 of culture. These results indicate that TGFβ1 is important for normal B cell developmentin vivo, and that B cell progenitors are differentially affected by the cytokine according to their stage of differentiation.


2007 ◽  
Vol 18 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Yasunari Takami ◽  
Tatsuya Ono ◽  
Tatsuo Fukagawa ◽  
Kei-ichi Shibahara ◽  
Tatsuo Nakayama

Chromatin assembly factor-1 (CAF-1), a complex consisting of p150, p60, and p48 subunits, is highly conserved from yeast to humans and facilitates nucleosome assembly of newly replicated DNA in vitro. To investigate roles of CAF-1 in vertebrates, we generated two conditional DT40 mutants, respectively, devoid of CAF-1p150 and p60. Depletion of each of these CAF-1 subunits led to delayed S-phase progression concomitant with slow DNA synthesis, followed by accumulation in late S/G2 phase and aberrant mitosis associated with extra centrosomes, and then the final consequence was cell death. We demonstrated that CAF-1 is necessary for rapid nucleosome formation during DNA replication in vivo as well as in vitro. Loss of CAF-1 was not associated with the apparent induction of phosphorylations of S-checkpoint kinases Chk1 and Chk2. To elucidate the precise role of domain(s) in CAF-1p150, functional dissection analyses including rescue assays were preformed. Results showed that the binding abilities of CAF-1p150 with CAF-1p60 and DNA polymerase sliding clamp proliferating cell nuclear antigen (PCNA) but not with heterochromatin protein HP1-γ are required for cell viability. These observations highlighted the essential role of CAF-1–dependent nucleosome assembly in DNA replication and cell proliferation through its interaction with PCNA.


1992 ◽  
Vol 25 (5) ◽  
pp. 563-576 ◽  
Author(s):  
JUN-ICHI HATA ◽  
JUNICHIRO FUJIMOTO ◽  
EIZABURO ISHII ◽  
AKIHIRO UMEZAWA ◽  
YASUO KOKAI ◽  
...  

1989 ◽  
Vol 9 (1) ◽  
pp. 57-66
Author(s):  
M Zuber ◽  
E M Tan ◽  
M Ryoji

Proliferating cell nuclear antigen (PCNA) (also called cyclin) is known to stimulate the activity of DNA polymerase delta but not the other DNA polymerases in vitro. We injected a human autoimmune antibody against PCNA into unfertilized eggs of Xenopus laevis and examined the effects of this antibody on the replication of injected plasmid DNA as well as egg chromosomes. The anti-PCNA antibody inhibited plasmid replication by up to 67%, demonstrating that PCNA is involved in plasmid replication in living cells. This result further implies that DNA polymerase delta is necessary for plasmid replication in vivo. Anti-PCNA antibody alone did not block plasmid replication completely, but the residual replication was abolished by coinjection of a monoclonal antibody against DNA polymerase alpha. Anti-DNA polymerase alpha alone inhibited plasmid replication by 63%. Thus, DNA polymerase alpha is also required for plasmid replication in this system. In similar studies on the replication of egg chromosomes, the inhibition by anti-PCNA antibody was only 30%, while anti-DNA polymerase alpha antibody blocked 73% of replication. We concluded that the replication machineries of chromosomes and plasmid differ in their relative content of DNA polymerase delta. In addition, we obtained evidence through the use of phenylbutyl deoxyguanosine, an inhibitor of DNA polymerase alpha, that the structure of DNA polymerase alpha holoenzyme for chromosome replication is significantly different from that for plasmid replication.


1991 ◽  
Vol 99 (2) ◽  
pp. 431-441
Author(s):  
A.J. Brown ◽  
E.J. Sanders

In the gastrulating chick embryo, the mesoderm cells arise from the epiblast layer by ingression through the linear accumulation of cells called the primitive streak. The mesoderm cells emerge from the streak with a fibroblastic morphology and proceed to move away from the mid-line of the embryo using, as a substratum, the basement membrane of the overlying epiblast and the extracellular matrix. We have investigated the roles of fibronectin and laminin as putative substrata for mesoderm cells using complementary in vivo and in vitro methods. We have microinjected agents into the tissue space adjacent to the primitive streak of living embryos and, after further incubation, we have examined the embryos for perturbation of the mesoderm tissue. These agents were: cell-binding regions from fibronectin (RGDS) and laminin (YIGSR), antibodies to these glycoproteins, and a Fab' fragment of the antibody to fibronectin. We find that RGDS, antibody to fibronectin, and the Fab' fragment cause a decrease in the number of mesoderm cells spread on the basement membrane, and a perturbation of cell shape suggesting locomotory impairment. No such influence was seen with YIGSR or antibodies to laminin. These results were extended using in vitro methods in which mesoderm cells were cultured in fibronectin-free medium on fibronectin or laminin in the presence of various agents. These agents were: RGDS; YIGSR; antibodies to fibronectin, fibronectin receptor, laminin and vitronectin; and a Fab' fragment of the fibronectin antiserum. We find that cell attachment and spreading on fibronectin is impaired by RGDS, antiserum to fibronectin, the Fab' fragment of fibronectin antiserum, and antiserum to fibronectin receptor. The results suggest that although the RGDS site in fibronectin is important, it is probably not the only fibronectin cell-binding site involved in mediating the behaviour of the mesoderm cells. Cells growing on laminin were perturbed by YIGSR, RGDS and antibodies to laminin, suggesting that mesoderm cells are able to recognise at least two sites in the laminin molecule. We conclude that the in vivo dependence of mesoderm cells on fibronectin is confirmed, but that although these cells have the ability to recognise sites in laminin as mediators of attachment and spreading, the in vivo role of this molecule in mesoderm morphogenesis is not yet certain.


Sign in / Sign up

Export Citation Format

Share Document