Body wall morphogenesis: Limb-genesis interferes with body wall-genesis via its influence on the abaxial somite derivatives

Abstract

The vertebrate body wall is regionalized into thoracic and lumbosacral/abdominal regions that differ in their morphology and developmental origin. The thoracic body wall has ribs and intercostal muscles, which develops from thoracic somites, whereas the abdominal wall has abdominal muscles, which develops from lumbosacral somites without ribs cage. To examine whether limb-genesis interferes with body wall-genesis, and to test the possibility that limb generation leads to the regional differentiation, an ectopic limb was induced in the thoracic region by transplanting prospective limb somatopleural mesoderm of Japanese quail between the ectoderm and somatopleural mesoderm of the chick prospective thoracic region. This ectopic limb generation induced the somitic cells to migrate into the ectopic limb mesenchyme to become its muscles and caused the loss of distal thoracic body wall (sterno-distal rib and distal intercostal muscle), without causing any significant effect on the more proximal region (proximal rib, vertebro-distal rib and proximal intercostal muscle). According to a new primaxial-abaxial classification, the proximal region is classified as primaxial and the distal region, as well as limb, is classified as abaxial. We demonstrated that ectopic limb development interfered with body wall development via its influence on the abaxial somite derivatives. The present study supports the idea that the somitic cells give rise to the primaxial derivatives keeping their own identity and fate, whereas they produce the abaxial derivatives responding to the lateral plate mesoderm.

Fixed cervical count and the origin of the mammalian diaphragm

“…5). This reasoning is supported by observations from chick limb induction experiments, which indicate that the commitment of somitic cells to the limbs in ectopic sites compromises the cellular contributions of these sites to other abaxial structures (Liem and Aoyama 2009). We therefore suggest that to the extent that a muscularized diaphragm was selectively advantageous in early mammals, anterior transposition of the limb field would be selected against, constraining reduction of cervical count.…”

Development of the Rectus Abdominis and Its Sheath in the Human Fetus

“…Such muscles have recently been termed abaxial muscles, rather than the classical name hypaxial muscles 21,22. Therefore, the rectus sheath also seems to originate from the lateral plate.…”

“…Using a chick-quail chimera system, Liem and Aoyama22 recently demonstrated that an ectopic limb experimentally induced on the superficial side of the lower chest wall often interfered with development of the rectus abdominis. The pectoralis-like muscle was observed to additionally appear in the original abdominal wall instead of the rectus abdominis, even though the chick rectus abdominis is derived from only 1 or 2 segmental anlagen.…”

Developmental stages of the Japanese quail

“…In developmental terms, quail is still an extremely popular animal model, with studies on neural crest, thyroid, heart, pancreas, spleen, intestinal and craniofacial development having been recently published (Chen et al 2008;Eames & Schneider, 2008;Hogers et al 2009;Quinn et al 2009;Rowan-Hull et al 2009). Quail are increasingly being used as a comparator organism in cellbased investigations and are still heavily utilized in chickquail chimeric studies (Binder et al 2008;Costa-Silva et al 2009;Grenier et al 2009;Liem & Aoyama, 2009). More recently, quail-duck chimeras have become a new model of choice of some groups (Lwigale & Schneider, 2008).…”