Cytoskeletal variations in an asymmetric cell division support diversity in nematode sperm size and sex ratios.
Development
; 144(18): 3253-3263, 2017 09 15.
Article
en En
| MEDLINE
| ID: mdl-28827395
Asymmetric partitioning is an essential component of many developmental processes. As spermatogenesis concludes, sperm are streamlined by discarding unnecessary cellular components into cellular wastebags called residual bodies (RBs). During nematode spermatogenesis, this asymmetric partitioning event occurs shortly after anaphase II, and both microtubules and actin partition into a central RB. Here, we use fluorescence and transmission electron microscopy to elucidate and compare the intermediate steps of RB formation in Caenorhabditis elegans, Rhabditis sp. SB347 (recently named Auanema rhodensis) and related nematodes. In all cases, intact microtubules reorganize and move from centrosomal to non-centrosomal sites at the RB-sperm boundary whereas actin reorganizes through cortical ring expansion and clearance from the poles. However, in species with tiny spermatocytes, these cytoskeletal changes are restricted to one pole. Consequently, partitioning yields one functional sperm with the X-bearing chromosome complement and an RB with the other chromosome set. Unipolar partitioning may not require an unpaired X, as it also occurs in XX spermatocytes. Instead, constraints related to spermatocyte downsizing may have contributed to the evolution of a sperm cell equivalent to female polar bodies.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Razón de Masculinidad
/
Espermatozoides
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Citoesqueleto
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Caenorhabditis elegans
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Tamaño de la Célula
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División Celular Asimétrica
Límite:
Animals
Idioma:
En
Revista:
Development
Asunto de la revista:
BIOLOGIA
/
EMBRIOLOGIA
Año:
2017
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido