Skeletal staining also showed assymetric shortening of the nasal bones, curving unilaterally in Alkbh1−/− mice causing mal-developed teeth (Fig. S4A), as well as reduced ossification in the phalanges (P) and the metatarsals (M) of the autopod of Alkbh1−/− newborns (Fig. S4B).
Reduced ossification of nasal, frontal, parietal, intraparietal, and supraoccipital bones, absence/gap between the ribs, reduced/fused sternebrae, vertebral centra, and caudal vertebrae, reduced pelvic elements, absence of carpals, metacarpals, tarsals, metatarsals, and phalanges were distinct.
In addition to its acute cytotoxicity, Cr VI) is a known developmental toxicant, causing postimplantation losses, resorptions, reduced fetal weight, and malformations including reduced ossification (Junaid et al. 1996; Kanojia et al. 1998).
This reduced ossification of various bones may be due to altered calcium metabolism or decreased calcium and magnesium ion levels as well as altered calcitonin level in the growing fetus, thereby causing retardation in bone development.
Other variations reported are commonly seen in rabbits (e.g. incomplete septation of lung lobes, irregular palatal rugae, blunt-tipped tail, irregular-shaped liver, globular-shaped kidneys, bilobed vertebral centra, reduced ossification of centra, sternebrae, pubis and skull).
Although total fetuses and litters with variations were not specifically reported, the types and incidence of fetuses with variations were primarily reduced ossification and there was no indication of a dose-related change.
Several studies on Wnt inhibitors have shown an increase of its expression in advanced carotid plaques (DKK1 antagonist) and in calcified aortas (SFRP1, -2, and -4), supporting the role of inhibitors in the establishment of a defensive response to reduce the activation of the Wnt pathway and, accordingly, to reduce ossification and avoid further atherosclerotic progression (9, 13).
Cartilaginous tissues are abundant in juveniles, but are reduced via ossification as fish age.
Kavlock et al. (1979) reported that high exposure to O3 (> 1.26 ppm) during organogenesis reduced skeletal ossification.
Striking examples of pedomorphic characters in pelagic and benthopelagic notothenioids include delayed and reduced skeletal ossification, retention of the notochord, reduced numbers of teeth and tooth rows, and reduction of the pterygoid process of the palatoquadrate [ 13, 15- 17].
In vivo, Rac1-deficient growth plates displayed delayed ossification, reduced chondrocyte proliferation and increased apoptosis, 9 partly due to reduced mitogenic activity through Rac1-iNOS-NO signalling.
