Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Choanocyte ultrastructure in halisarca dujardini (Demospongiae, Halisarcida). / Gonobobleva, Elisaveta; Maldonado, Manuel.
в: Journal of Morphology, Том 270, № 5, 01.05.2009, стр. 615-627.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Choanocyte ultrastructure in halisarca dujardini (Demospongiae, Halisarcida)
AU - Gonobobleva, Elisaveta
AU - Maldonado, Manuel
PY - 2009/5/1
Y1 - 2009/5/1
N2 - Understanding poriferan choanocyte ultra-structure is crucial if we are to unravel the steps of a putative evolutionary transition between choanoflagel-late protists and early metazoans. Surprisingly, some aspects of choanocyte cytology still remain little investigated. This study of choanocyte ultrastructure in the halisarcid demosponge Halisarca dujardini revealed a combination of minor and major distinctive traits, some of them unknown in Porifera so far. Most significant features were 1) an asymmetrical periflagellar sleeve, 2) a battery of specialized intercellular junctions at the lateral cell surface complemented with an array of lateral interdigitations between adjacent choanocytes that provides a particular sealing system of the choanoderm, and 3) a unique, unexpectedly complex, basal apparatus. The basal apparatus consists of a basal body provided with a small basal foot and an intricate transverse skeleton of microtubules. An accessory centriole, which is not perpendicular to the basal body, is about 45°. In addition, a system of short striated rootlets (periodicity = 50-60 nm) arises from the proximal edge of the basal body and runs longitudinally to contact the nuclear apex. This is the first flagellar rootlet system ever found in a choanocyte. The accessory centriole, the rootlet system, and the nuclear apex are all encircled by a large Golgi apparatus, adding another distinctive feature to the choanocyte cytology. The set of distinct features discovered in the choanocyte of H. dujardini indicates that the ultrastructure of the poriferan choanocyte may vary substantially between sponge groups. It is necessary to improve understanding of such variation, as the cytolog-ical features of choanocytes are often coded as characters both for formulation of hypotheses on the origin of animals and inference of phylogenetic relationships at the base of the metazoan tree. J. Morphol.
AB - Understanding poriferan choanocyte ultra-structure is crucial if we are to unravel the steps of a putative evolutionary transition between choanoflagel-late protists and early metazoans. Surprisingly, some aspects of choanocyte cytology still remain little investigated. This study of choanocyte ultrastructure in the halisarcid demosponge Halisarca dujardini revealed a combination of minor and major distinctive traits, some of them unknown in Porifera so far. Most significant features were 1) an asymmetrical periflagellar sleeve, 2) a battery of specialized intercellular junctions at the lateral cell surface complemented with an array of lateral interdigitations between adjacent choanocytes that provides a particular sealing system of the choanoderm, and 3) a unique, unexpectedly complex, basal apparatus. The basal apparatus consists of a basal body provided with a small basal foot and an intricate transverse skeleton of microtubules. An accessory centriole, which is not perpendicular to the basal body, is about 45°. In addition, a system of short striated rootlets (periodicity = 50-60 nm) arises from the proximal edge of the basal body and runs longitudinally to contact the nuclear apex. This is the first flagellar rootlet system ever found in a choanocyte. The accessory centriole, the rootlet system, and the nuclear apex are all encircled by a large Golgi apparatus, adding another distinctive feature to the choanocyte cytology. The set of distinct features discovered in the choanocyte of H. dujardini indicates that the ultrastructure of the poriferan choanocyte may vary substantially between sponge groups. It is necessary to improve understanding of such variation, as the cytolog-ical features of choanocytes are often coded as characters both for formulation of hypotheses on the origin of animals and inference of phylogenetic relationships at the base of the metazoan tree. J. Morphol.
KW - Basal apparatus
KW - Cell junctions
KW - Periflagellar sleeve
KW - Sponges
KW - Striated rootlet
UR - http://www.scopus.com/inward/record.url?scp=66149087092&partnerID=8YFLogxK
U2 - 10.1002/jmor.10709
DO - 10.1002/jmor.10709
M3 - Article
C2 - 19107941
AN - SCOPUS:66149087092
VL - 270
SP - 615
EP - 627
JO - Journal of Morphology
JF - Journal of Morphology
SN - 0362-2525
IS - 5
ER -
ID: 40337433