TY - JOUR
T1 - Early development in the velvet worm Euperipatoides kanangrensis Reid 1996 (Onychophora:Peripatopsidae)
AU - Eriksson, Bo Joakim
AU - Tait, Noel N.
PY - 2012/9
Y1 - 2012/9
N2 - We present here a description of early development in the onychophoran Euperipatoides kanangrensis with emphasis on processes that are ambiguously described in older literature. Special focus has been on the pattern of early cleavage, blastoderm and germinal disc development and gastrulation. The formation of the blastopore, stomodeum and proctodeum is described from sectioned material using light and transmission electron microscopy as well as whole-mount material stained for nuclei and gene expression. The early cleavages were found to be superficial, contrary to earlier descriptions of cleavage in yolky, ovoviviparous onychophorans. Also, contrary to earlier descriptions, the embryonic anterior-posterior axis is not predetermined in the egg. Our data support the view of a blastopore that becomes elongated and slit-like, resembling some of the earliest descriptions. From gene expression data, we concluded that the position of the proctodeum is the most posterior pit in the developing embryo. This description of early development adds to our knowledge of the staging of embryonic development in onychophorans necessary for studies on the role of developmental changes in evolution.
AB - We present here a description of early development in the onychophoran Euperipatoides kanangrensis with emphasis on processes that are ambiguously described in older literature. Special focus has been on the pattern of early cleavage, blastoderm and germinal disc development and gastrulation. The formation of the blastopore, stomodeum and proctodeum is described from sectioned material using light and transmission electron microscopy as well as whole-mount material stained for nuclei and gene expression. The early cleavages were found to be superficial, contrary to earlier descriptions of cleavage in yolky, ovoviviparous onychophorans. Also, contrary to earlier descriptions, the embryonic anterior-posterior axis is not predetermined in the egg. Our data support the view of a blastopore that becomes elongated and slit-like, resembling some of the earliest descriptions. From gene expression data, we concluded that the position of the proctodeum is the most posterior pit in the developing embryo. This description of early development adds to our knowledge of the staging of embryonic development in onychophorans necessary for studies on the role of developmental changes in evolution.
UR - http://www.scopus.com/inward/record.url?scp=84865401624&partnerID=8YFLogxK
U2 - 10.1016/j.asd.2012.02.009
DO - 10.1016/j.asd.2012.02.009
M3 - Article
C2 - 22430148
AN - SCOPUS:84865401624
VL - 41
SP - 483
EP - 493
JO - Arthropod Structure and Development
JF - Arthropod Structure and Development
SN - 1467-8039
IS - 5
ER -