scholarly journals Gonadal status of male recipient mice influences germ cell development in immature buffalo testis tissue xenograft

Reproduction ◽  
2012 ◽  
Vol 143 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Niranjan Reddy ◽  
Ranjeet Singh Mahla ◽  
Revanth Thathi ◽  
Sanjay Kumar Suman ◽  
Jedy Jose ◽  
...  

Growth and development of immature testis xenograft from various domestic mammals has been shown in mouse recipients; however, buffalo testis xenografts have not been reported to date. In this study, small fragments of testis tissue from 8-week-old buffalo calves were implanted subcutaneously onto the back of immunodeficient male mouse recipients, which were either castrated or left intact (non-castrated). The xenografts were retrieved and analyzed 12 and 24 weeks later. The grafted tissue survived and grew in both types of recipient with a significant increase in weight and seminiferous tubule diameter. Recovery of grafts from intact recipients 24 weeks post-grafting was significantly lower than that from the castrated recipients. Seminal vesicle indices and serum testosterone levels were lower in castrated recipients at both collection time points in comparison to the intact recipients and non-grafted intact mouse controls. Pachytene spermatocytes were the most advanced germ cells observed in grafts recovered from castrated recipients 24 weeks post-grafting. Complete spermatogenesis, as indicated by the presence of elongated spermatids, was present only in grafts from intact recipients collected 24 weeks post-grafting. However, significant number of germ cells with DNA damage was also detected in these grafts as indicated by TUNEL assay. The complete germ cell differentiation in xenografts from intact recipients may be attributed to efficient Sertoli cell maturation. These results suggest that germ cell differentiation in buffalo testis xenograft can be completed by altering the recipient gonadal status.

2007 ◽  
Vol 19 (1) ◽  
pp. 119
Author(s):  
L. Arregui ◽  
R. Rathi ◽  
W. Zeng ◽  
A. Honaramooz ◽  
M. Gomendio ◽  
...  

Testis tissue grafting presents an option for preservation of genetic material when sperm recovery is not possible. Grafting of testis tissue from sexually immature males to immunodeficient mice results in germ cell differentiation and production of fertilization-competent sperm from different mammalian species (Honaramooz et al. 2002 Nature 418, 778–781). However, the efficiency of testis tissue xenografting from adult donors has not been critically evaluated. Spermatogenesis was arrested at meiosis in grafts from mature horses (Rathi et al. 2006 Reproduction 131, 1091–1098) and hamsters (Schlatt et al. 2002 Reproduction 124, 339–346), and no germ cell differentiation occurred in xenografts of adult human testis tissue (Schlatt et al. 2006 Hum. Reprod. 21, 384–389). The objective of this study was to investigate survival and germ cell differentiation of testis xenografts from sexually mature donors of different species. Small fragments of testis tissue from 10 donor animals of 5 species were grafted under the back skin of immunodeficient, castrated male mice (n = 37, 2–6/donor). Donors were pig (8 months old), goat (18 months old and 4 years old) (n = 2), bull (3 years old), donkey (13 months old), and rhesus monkey (3, 6, 11, and 12 years old). At the time of grafting, donor tissue contained elongated spermatids, albeit to different degrees (>75% of seminiferous tubules in testis tissue from pig, goat, bull, and 6–12-year-old monkeys, and 33 or 66% of tubules in tissue from donkey or 3-year-old monkey, respectively). Grafts were recovered <12 weeks (n = 14 mice), 12–24 weeks (n = 16 mice), and >24 weeks (n = 7 mice) after grafting and classified histologically as completely degenerated (no tubules found), degenerated tubules (only hyalinized seminiferous tubules observed), or according to the most advanced type of germ cell present. Grafts from pig, goat, bull, and 6–12-year-old monkeys contained >60% degenerated tubules or were completely degenerated at all time points analyzed. In contrast, in grafts from the 3-year-old monkey, only 18% of tubules were degenerated, 14% contained Sertoli cells only, 64% contained meiotic, and 4% haploid germ cells at 24 weeks after grafting. Similarly, donkey testis grafts recovered 12–24 weeks after grafting contained <2% degenerated tubules, 46% of tubules had Sertoli cells only, 45% contained meiotic, and 7% haploid germ cells. These results show that survival and differentiation of germ cells in testis grafts from sexually mature mammalian donors is poor. However, better graft survival and maintenance of spermatogenesis occurred in donor tissue from donkey and 3-year-old monkey that were less mature at the time of grafting. Therefore, species and age-related differences appear to exist with regard to germ cell survival and differentiation in xenografts from adult donors. This work was supported by USDA/CSREES 03-35203-13486, NIH/NCRR 5-R01-RR17359-05, the Spanish Ministry of Education, and Science (BES-2004-4112).


2005 ◽  
Vol 17 (2) ◽  
pp. 247 ◽  
Author(s):  
A. Honaramooz ◽  
W. Zeng ◽  
R. Rathi ◽  
J. Koster ◽  
O. Ryder ◽  
...  

In April 2003, two banteng (Bos javonicus) calves were born after heterologous nuclear transfer of donor cells from a genetically valuable individual frozen in 1978. One of the cloned banteng calves died at one week of age. The calf was found to have one scrotal and one abdominally cryptorchid testis. In an attempt to preserve male germ cells from this valuable animal, parts of each testis were shipped on ice to the University of Pennsylvania for xenografting. Grafting of testis tissue from immature domestic animals and monkeys under the back skin of immunodeficient mice can result in complete spermatogenesis, albeit with different levels of efficiency in different species. The objective of this experiment was to investigate if grafting of immature banteng testis tissue would result in spermatogenesis in a mouse host. Small fragments of tissue (about 1 mm, 3 each) from both testes were grafted under the back skin (4 pieces of scrotal testis on the right side and 4 pieces of retained testis on the left side) of 6 castrated male immunodeficient mice. Histological examination of the testis xenografts was performed 3, 6, 9, 12, and 15 months after transplantation. Weight of the seminal vesicles in the host mouse was recorded as an indicator of bioactive testosterone produced by the xenografts. At the time of grafting, both testes contained seminiferous cords with immature Sertoli cells and gonocytes. At 3, 6, and 9 months after grafting, pachytene spermatocytes were present in the xenografts of the scrotal testis whereas no germ cell differentiation was observed in grafts from the retained testis. However, spermatogenesis in grafts of the scrotal testis did not proceed further through meiosis in grafts analyzed at 12 and 15 months after grafting, with pachytene spermatocytes still the most advanced germ cell type present in grafts recovered 15 months after grafting. The weight of the seminal vesicles in the castrated host mice was restored to pre-castration values showing that xenografts were releasing bioactive testosterone. These results indicate that banteng spermatogenesis was initiated in the mouse host but became arrested at meiosis as observed previously in xenografts of immature bovine or equine testis. Therefore, haploid germ cells could not be recovered. This represents the first example of trying to preserve fertility from a rare, valuable newborn animal by testis tissue xenografting. While xenografting presents a previously unavailable option for preservation of male germ cells from immature individuals, the efficiency of sperm production in testis xenografts appears to be variable and has to be determined empirically for different donor species. This work was supported by USDA 03-35203-13486.


Reproduction ◽  
2013 ◽  
Vol 146 (5) ◽  
pp. 471-480 ◽  
Author(s):  
Gerardo M Oresti ◽  
Jesús García-López ◽  
Marta I Aveldaño ◽  
Jesús del Mazo

Male germ cell differentiation entails the synthesis and remodeling of membrane polar lipids and the formation of triacylglycerols (TAGs). This requires fatty acid-binding proteins (FABPs) for intracellular fatty acid traffic, a diacylglycerol acyltransferase (DGAT) to catalyze the final step of TAG biosynthesis, and a TAG storage mode. We examined the expression of genes encoding five members of the FABP family and two DGAT proteins, as well as the lipid droplet protein perilipin 2 (PLIN2), during mouse testis development and in specific cells from seminiferous epithelium.Fabp5expression was distinctive of Sertoli cells and consequently was higher in prepubertal than in adult testis. The expression ofFabp3increased in testis during postnatal development, associated with the functional differentiation of interstitial cells, but was low in germ cells.Fabp9, together withFabp12, was prominently expressed in the latter. Their transcripts increased from spermatocytes to spermatids and, interestingly, were highest in spermatid-derived residual bodies (RB). Both Sertoli and germ cells, which produce neutral lipids and store them in lipid droplets, expressedPlin2. Yet, whileDgat1was detected in Sertoli cells,Dgat2accumulated in germ cells with a similar pattern of expression asFabp9. These results correlated with polyunsaturated fatty acid-rich TAG levels also increasing with mouse germ cell differentiation highest in RB, connecting DGAT2 with the biosynthesis of such TAGs. The age- and germ cell type-associated increases inFabp9,Dgat2, andPlin2levels are thus functionally related in the last stages of germ cell differentiation.


2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Min Chen ◽  
Min Chen ◽  
Suren Chen ◽  
Jingjing Zhou ◽  
Fangfang Dong ◽  
...  

The interaction between germ cell and somatic cell plays important roles in germ cell development. However, the exact function of gonad somatic cell in germ cell differentiation is unclear. In the present study, the function of gonad somatic cell in germ cell meiosis was examined by using mouse models with aberrant somatic cell differentiation. In Wt1R394W/R394W mice, the genital ridge is absent due to the apoptosis of coelomic epithelial cells. Interestingly, in both male and female Wt1R394W/R394W germ cells, STRA8 was detected at E12.5 and the scattered SYCP3 foci were observed at E13.5 which was consistent with control females. In Wt1-/flox; Cre-ERTM mice, Wt1 was inactivated by the injection of tamoxifen at E9.5 and the differentiation of Sertoli and granulosa cells was completely blocked. We found that most germ cells were located outside of genital ridge after Wt1 inactivation. STRA8, SYCP3, and γH2AX proteins were detected in germ cells of both male and female Wt1-/flox; Cre-ERTM gonads, whereas no thread-like SYCP3 signal was observed. Our study demonstrates that aberrant development of gonad somatic cells leads to ectopic expression of meiosis-associated genes in germ cells, but meiosis was arrested before prophase I. These results suggest that the proper differentiation of gonad somatic cells is essential for germ cell meiosis.


Reproduction ◽  
2005 ◽  
Vol 130 (6) ◽  
pp. 923-929 ◽  
Author(s):  
Rahul Rathi ◽  
Ali Honaramooz ◽  
Wenxian Zeng ◽  
Stefan Schlatt ◽  
Ina Dobrinski

Spermatogenesis can occur in testis tissue from immature bulls ectopically grafted into mouse hosts; however, efficiency of sperm production is lower than in other donor species. To elucidate a possible mechanism for the impaired spermatogenesis in bovine testis xenografts, germ cell fate and xenograft development were investigated at different time points and compared with testis tissue from age-matched calves as controls. Histologically, an initial decrease in germ cell number was noticed in xenografts recovered up to 2 months post-grafting without an increase in germ cell apoptosis. From 2 months onward, the number of germ cells increased. In contrast, a continuous increase in germ cell number was seen in control tissue. Pachytene spermatocytes were observed in some grafts before 4 months, whereas in the control tissue they were not present until 5 months of age. Beyond 4 months post-grafting spermatogenesis appeared to be arrested at the pachytene spermatocyte stage in most grafts. Elongated spermatids were observed between 6 and 8 months post-grafting, similar to the controls, albeit in much lower numbers. Lumen formation started earlier in grafts compared with controls and by 6 months post-grafting tubules with extensively dilated lumen were observed. A donor effect on efficiency of spermatogenesis was also observed. These results indicate that the low efficiency of sperm production in bovine xenografts is due to an initial deficit of germ cells and impaired meiotic and post-meiotic differentiation. The characterization of spermatogenic efficiency will provide the basis to understand the control of spermatogenesis in testis grafts.


2010 ◽  
Vol 22 (9) ◽  
pp. 85
Author(s):  
E. A. McLaughlin ◽  
B. A. Fraser ◽  
V. Pye ◽  
M. Bigland ◽  
N. A. Siddall ◽  
...  

Mammalian meiosis is a tightly regulated process involving specialized cell cycle progression and morphogenetic changes. We have demonstrated that the Musashi family of RNA binding proteins is implicated in the regulation of spermatogonial stem self renewal and germ cell differentiation. Here we describe the novel mechanism by which the Musashi family proteins, Msi1 and Msi2, act to control exit from spermatogonial mitotic amplification and normal entry into meiosis. Gene and protein analysis indicated overlapping Msi1 and Msi2 profiles in enriched populations of isolated germ cells and reciprocal subcellular expression patterns in spermatogonia and pachytene spermatocytes/ round spermatids in testes sections. Recombinant Msi1 protein-RNA pulldown and microarray analysis coupled with in vitro shRNA knockdown studies in spermatogonial culture and subsequent immunoprecipitation and qPCR established that Msi1 targeted Msi2 mRNA for post transcriptional translational repression. Immunoprecipitation of Msi2 target mRNA and subsequent qPCR together with in vitro shRNA knockdown studies inround spermatidculture identified a cell cycle inhibitor protein CDKN1C (p57kip2) as the principal target of Msi2 translational inhibition. Immunolocalisation of CDKN1C protein indicated that expression of this cell cycle regulator coincided with the nuclear import of Msi1 and the appearance of cytoplasmic Msi2 expression in early pachytene spermatocytes. Using a transgenic Msi1 overexpression mouse model in conjunction with quantitative gene and protein expression, we confirmed Msi1 targeting of Msi2 and subsequent Msi2 targeting of CDKN1C for translational repression in vivo. Ectopic overexpression of Msi1 in germ cellsinduces substantial Msi2 downregulation and aberrant CDKN1C expression, resulting in abnormal spermatogenic differentiation, germ cell apoptosis/arrest and sterility. In conclusion, our results indicate a sophisticated molecular switch encompassing cell cycle protein regulation by Musashi family proteins, is required for normal exit from mitotic division, entry into meiosis and post meiotic germ cell differentiation.


2010 ◽  
Vol 22 (1) ◽  
pp. 315
Author(s):  
J. R. Rodriguez-Sosa ◽  
G. M. J. Costa ◽  
R. Rathi ◽  
L. R. França ◽  
I. Dobrinski

In rodents, thyroid hormones inhibit Sertoli cell proliferation, promote Sertoli cell differentiation, and accelerate lumen formation in the seminiferous tubules. Conversely, transient hypothyroidism prolongs Sertoli cell proliferation, leading to increased Sertoli cell number and testicular size. In order to evaluate whether 6-N-propyl-2-thiouracil (PTU)-induced hypothyroidism in the host mouse would affect seminiferous tubule development and germ cell differentiation, and subsequently increase spermatogenesis in bovine testis xenografts, fragments (∼1 mm3) of testes from 1-wk-old Holstein calves (n = 6) were transplanted ectopically to castrated immunodeficient male mice (n = 6/donor). Mice (n = 3/donor) were treated with 0.1% (w/v) PTU in drinking water for 4 weeks or left as control. At 5 and 7 months after grafting, grafts were analyzed by morphometry and immunohistochemistry for expression of protein gene product 9.5 (PGP 9.5) as a germ cell marker, and Mullerian-inhibiting substance (MIS) and androgen receptor (AR) to assess Sertoli cell maturation. For each variable, averages of each group were compared at each collection point by t-test PTU treatment to the drinking water for 1 month suppressed thyroid hormone levels (T4) in host mice without negative systemic effects (0.3 ± 0.2 v. 4 ± 0.3 μg dL-1 at 4 weeks in treated v. control mice, respectively, P < 0.05). Spermatogenesis in recovered grafts was arrested at meiosis regardless of treatment and collection time. Graft weight was lower in treated mice than in controls (21 ± 4 v. 42 ± 5 and 24 ± 9 v. 51 ± 5 mg, at 5 and 7 months, respectively, P < 0.05). Volume density of the tubular and intertubular compartments, and seminiferous epithelium, was not affected by treatment (P > 0.05); however, treatment reduced lumen density compared to controls (9 ± 2 v. 19 ± 3 and 12 ± 1 v. 24 ± 4%) and tubular diameter (121 ± 3 v. 140 ± 7 and 144 ± 2v. 170 ± 2 (im, at 5 and 7 months, respectively (P < 0.05). Tubule length per milligram was not different at 5 months between control and treated groups (P > 0.05) but was increased at 7 months in the treated grafts (50 ± 1 v. 30 ± 1 cm, P < 0.05). Number of Sertoli cells per milligram was not affected by treatment (P > 0.05). However, Sertoli cell volume was increased in controls (440 ± 19 v. 341 ± 14 and 504 ± 6 v. 388 ± 18 μm3, at 5 and 7 months, respectively, P < 0.05). The number of germ cells per 100 Sertoli cells was not different between groups at any collection time (P > 0.05). Sertoli cells showed variable MIS expression and lack of or weak AR expression regardless of treatment and collection time, indicating an immature phenotype. In conclusion, suppression of thyroid hormone levels in host mice affects seminiferous tubule development in bovine testis xenografts, demonstrating that endocrine manipulation of the mouse host will affect xenografts in a predictable manner. However, treatment did not affect number and differentiation of germ cells. Rather, incomplete Sertoli cell maturation appears to lead to incomplete germ cell differentiation in bovine testis xenografts. Supported by USDA (2007-35203-18213).


Development ◽  
1986 ◽  
Vol 94 (1) ◽  
pp. 83-93
Author(s):  
J. H. Cleine

The genital ridges of Xenopus laevis tadpoles reared from eggs kept in an inverted position contain less than 40 % of the number of primordial germ cells (PGCs) of controls (Cleine & Dixon, 1985). It has been suggested that this reduction is caused by the germ cells' ectopic position in the anterior endoderm of larvae from inverted eggs, from where they may be unable to migrate into the genital ridges (Cleine & Dixon, 1985). This hypothesis is tested here by interchanging anterior and posterior endodermal grafts between pairs of inverted embryos at the early tailbud stage. Replacement of anterior by posterior endoderm has no effect but replacement of posterior by anterior endoderm increases the number of PGCs in the genital ridges and significantly reduces the proportion of sterile embryos. In a control series, in which the same type of grafting was done with normal embryos, replacement of posterior by anterior endoderm reduced the number of germ cells to almost zero, but replacement of anterior by posterior endoderm nearly doubled it. These findings are explained in terms of the distribution of the germ cells in the endoderm at the time of grafting. The results firstly show that the position of the germ cells is crucial to successful migration and secondly they support the notion that germ plasm has a determinative role during early germ cell differentiation.


Reproduction ◽  
2016 ◽  
Vol 151 (6) ◽  
pp. 673-681 ◽  
Author(s):  
Ma Tian-Zhong ◽  
Chen Bi ◽  
Zhang Ying ◽  
Jing Xia ◽  
Peng Cai-Ling ◽  
...  

Abstract Emx2 deletion impairs the growth and maintenance of the genital ridge. However, its role in subsequent germ cell differentiation during embryonic stages is unknown. Using a tamoxifen-inducible Cre-loxP mouse model (Emx2flox/flox, Cre-ERTM, hereafter called as Emx2 knockdown), we showed that germ cell differentiation was impaired in Emx2-knockdown testes. Representative characteristics of male germ cell differentiation, including a reduced ability to form embryonic germ (EG) cell colonies in vitro, down-regulation of pluripotency markers and G1/G0 arrest, did not occur in Emx2-knockdown testes. Furthermore, FGF9 and NODAL signalling occurred at abnormally high levels in Emx2-knockdown testes. Both blocking FGF9 signalling with SU5402 and inhibiting NODAL signalling with SB431542 allowed germ cells from Emx2-knockdown testes to differentiate in vitro. Therefore, EMX2 in somatic cells is required to trigger germ cell differentiation in XY foetuses, posterior to its previously reported role in the growth and maintenance of the genital ridge.


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