Original article http://dx.doi.org/10.4322/jms.107816 Morphological development of the testicles and spermatogenesis in guinea pigs (Cavia porcellus Linnaeus, 1758) NUNES, A. K. R.1, SANTOS, J. M.1, GOUVEIA, B. B.1, MENEZES, V. G.1, MATOS, M. H. T.2, FARIA, M. D.3 and GRADELA, A.3* 1Projeto de Irrigação Senador Nilo Coelho, Universidade Federal do Vale de São Francisco – UNIVASF, Rod. BR 407, sn, Km 12, Lote 543, C1, CEP 56300-990, Petrolina, PE, Brazil 2Projeto de Irrigação Senador Nilo Coelho, Medicina Veterinária, Núcleo de Biotecnologia Aplicada ao Desenvolvimento Folicular Ovariano, Colegiado de Medicina Veterinária, Universidade Federal do Vale do São Francisco – UNIVASF, Rod. BR 407, sn, Km 12, Lote 543, C1, CEP 56300-990, Petrolina, PE, Brazil 3Projeto de Irrigação Senador Nilo Coelho, Laboratório de Anatomia dos Animais Domésticos e Silvestres, Colegiado de Medicina Veterinária, Universidade Federal do Vale do São Francisco – UNIVASF, Rod. BR 407, sn, Km 12, Lote 543, C1, CEP 56300-990, Petrolina, PE, Brazil *E-mail:
[email protected] Abstract Introduction: Understanding the dynamics of spermatogenesis is crucial to clinical andrology and to understanding the processes which define the ability to produce sperm. However, the entire process cannot be modeled in vitro and guinea pig may be an alternative as animal model for studying human reproduction. Objective: In order to establish morphological patterns of the testicular development and spermatogenesis in guinea pigs, we examined testis to assess changes in the testis architecture, transition time from spermatocytes to elongated spermatids and stablishment of puberty. Materials and methods: We used macroscopic analysis, microstructural analysis and absolute measures of seminiferous tubules by light microscopy in fifty-five guinea pigs from one to eleven weeks of age.