The initial maturation status of marmoset testicular tissues has an impact on germ cell maintenance and somatic cell response in tissue fragment culture

Abstract

Successful in vitro spermatogenesis was reported using immature mouse testicular tissues in a fragment culture approach, raising hopes that this method could also be applied for fertility preservation in humans. Although maintaining immature human testicular tissue fragments in culture is feasible for an extended period, it remains unknown whether germ cell survival and the somatic cell response depend on the differentiation status of tissue. Employing the marmoset monkey (Callithrix jacchus), we aimed to assess whether the maturation status of prepubertal and peri-/pubertal testicular tissues influence the outcome of testis fragment culture. Testicular tissue fragments from 4- and 8-month-old (n = 3, each) marmosets were cultured and evaluated after 0, 7, 14, 28 and 42 days. Immunohistochemistry was performed for identification and quantification of germ cells (melanoma-associated antigen 4) and Sertoli cell maturation status (anti-Müllerian hormone: AMH). During testis fragment culture, spermatogonial numbers were significantly reduced (P < 0.05) in the 4- but not 8-month-old monkeys, at Day 0 versus Day 42 of culture. Moreover, while Sertoli cells from 4-month-old monkeys maintained an immature phenotype (i.e. AMH expression) during culture, AMH expression was regained in two of the 8-month-old monkeys. Interestingly, progression of differentiation to later meiotic stage was solely observed in one 8-month-old marmoset, which was at an intermediate state regarding germ cell content, with gonocytes as well as spermatocytes present, as well as Sertoli cell maturation status. Although species-specific differences might influence the outcome of testis fragment experiments in vitro, our study demonstrated that the developmental status of the testicular tissues needs to be considered as it seems to be decisive for germ cell maintenance, somatic cell response and possibly the differentiation potential.

Microfluidic and Static Organotypic Culture Systems to Support Ex Vivo Spermatogenesis From Prepubertal Porcine Testicular Tissue: A Comparative Study

“…Similar to other studies ( de Michele et al, 2018 ; Heckmann et al, 2020 ; Sharma et al, 2022 ), germ cell differentiation progressed as expected (first SYCP3 and then CREM) and was accelerated in vitro . While both spermatocytes and presumptive spermatids were observed in all systems, their numbers per ST cross-section were higher in the AGPC group.…”

“…The overall presence of tissue core degeneration, loss of both the ST integrity and undifferentiated spermatogonia numbers, as well as the increase in apoptosis over the culture period were disappointing, although not surprising. Such phenomena are still a hurdle in in vitro experiments across all species, including mice, rats, non-human primates, and humans ( Reda et al, 2016 ; de Michele et al, 2017 ; Medrano et al, 2018 ; Portela et al, 2019a ; Portela et al, 2019b ; Abe et al, 2020 ; Heckmann et al, 2020 ; Kurek et al, 2021 ; Sharma et al, 2022 ).…”

“…Yet, despite long-lasting efforts, IVM of prepubertal testicular tissue from rats ( Reda et al, 2016 ; Matsumura et al, 2021 ; Saulnier et al, 2021 ) and larger mammals ( Heckmann et al, 2020 ; Sharma et al, 2022 ) including humans ( de Michele et al, 2017 ; Medrano et al, 2018 ; Portela et al, 2019a ; Kurek et al, 2021 ) remained disappointing compared to achievements in mice where fertilization-competent spermatozoa leading to live births were produced ( Sato et al, 2011 ; Yokonishi et al, 2014 ; Komeya et al, 2016 ) although the success of in vitro spermatogenesis in the latter species seemed to be strain-dependent ( Portela et al, 2019b ). In the best-case scenario for humans, few haploid germ cells were produced in vitro starting from SSCs found within a testicular cell suspension ( Abofoul-Azab et al, 2018 ) or from intact ITT fragments of prepubertal boys ( de Michele et al, 2018 ).…”

Rat in vitro spermatogenesis promoted by chemical supplementations and oxygen-tension control

“…It is certainly important to study IVS with different animal species for comparison and to extract principles of spermatogenesis. Previous reports using different animal species, including cats, marmosets, and humans, examined variety of culture conditions 11,[13][14][15][16] . In particular, effect of hormones has been extensively examined, with some reporting positive effects and others not [13][14][15]19 .…”

Transcriptome Profiling of Different State Callus Induced from Immature Embryo in Maize

“…e establishment of a suitable transformation receptor system is a key link in maize genetic transformation [56,57]. Effective somatic cell reproduction and regeneration system is one of the preconditions for plant genetic transformation, which is related to whether suitable transformation receptor materials can be provided and whether normal transgenic plants can be successfully regenerated after transformation [58][59][60][61].…”