ISSN:
0148-7280
Schlagwort(e):
sperm morphometrics
;
egg-acrosome correlation
;
Oligochaeta
;
Annelida
;
Life and Medical Sciences
;
Cell & Developmental Biology
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Biologie
Notizen:
Ultrastructural variation between spermatozoa of nine lumbricid species has examined for Prearson r correlations, by principal components and coordinates analysis, and graphically, with particular reference to the acrosmoe. Results are compared with a survey of acrosome in seven other oligochaete families. Acrosome lengths correlates highly with length of the primary acrosome vesicle (PAV) though absolute lengths of the two in an acrosome may differ greatly. High correlation ofacrosome lenghts with thickness of the zone pellucida of the oocyte in lumbricida and other families is consistent with the hypothesis that intertaxon variation in acrosome length in an adaptation to the thickness of the zona. This variation is brought about by variation in the length of the acrosome tube, which is a unique structure of the Clitellasta. Correlation with zona thickness is considered premarily to be that of the acrosome (and tube) length and not of the PVA. Other sperm components do not show high correlation with zona depth, except an enigmatic correlation re of axial rod width. Lumbricid arcosome lenght shows a moderate positive allometry relative to zona depth. The short acrosome of Tubificidae and Enchytraeidae (microdriles) correlate with short oocyte microvilli and narrow zonae. Acrosome lenght-zona correlation is not a secondary expression of body size (which varies indiscriminately in lumbricids) or egg size; microdriles have larger eggs than megadriles. Mwgadrile features of the acrosome of the tubificidan Phreodrilus, including greater length, are attributed to postulated internal fertilization. It is suggested that the oliochatee acrosome penetrates the zone between, and possibly manipulated by, its microvilli before the acrosome reaction (which is briefly charaterized electron microscopically) occurs or progresses far.
Zusätzliches Material:
32 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/mrd.1120080205
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