Loss of function of tbx2a resulted in similar heart defects, with incomplete looping and lack of AVC constriction (Fig. 1G,L).
Alternatively, these defects may be caused by lack of apical constriction, a cell behavior that is essential for neural plate bending along the mediolateral axis (Ossipova et al., 2014; Sawyer et al., 2010; Schroeder, 1970; Suzuki et al., 2012).
From the lack of waistlike constrictions, Dr. Fisher knew he had found more Adetomyrma, thousands of them.
The presence of holocentric chromosomes was reported based on the cytological observations, including the lack of primary constrictions and parallel sister chromatid migration during anaphase.
L. ripura has the smallest number of chromosomes with the largest relative length facilitating the assessment of lack of primary constrictions (Ortiz, 1969).
This is reflected in the lack of a secondary constriction at the rDNA locus on chromosomes Apo and Dpo in this individual (Figure 2, Table 3).
Holokinetic chromosomes are characterized by the lack of a distinct primary constriction (the localized centromere), and their large kinetochore plates, also referred to as diffuse centromeres, cover a significant portion of the poleward surface of each sister chromatid [54], [55].
Moreover, the holokinetic nature of lepidopteran chromosomes, i.e. the lack of a distinct primary constriction (the centromere), is expected to facilitate karyotype evolution mainly via chromosomal fusion and fission by reducing the risk of formation of dicentric and acentric chromosomes [ 23].
These patterns of cell proliferation and apoptosis were also seen in the developing maxillary incisor region of Gas1 −/− and Boc −/− mice, although in the Gas1 mutant there was evidence of constriction and a lack of development across the midline (Fig. 9E L).
On the other hand, atropine (a cholinergic receptor antagonist) and haloperidol (a dopaminergic receptor antagonist) did not cause any significant changes in the number of abdominal constrictions, indicating lack of involvement of those receptor systems in MEMC antinociception.
Dauer larvae undergo morphological and metabolic changes that allow them to survive harsh environmental conditions, such as radial constriction of the body and constriction of the pharynx, lack of pharyngeal pumping, closure of oral cavities, and the formation of a specialized cuticle with lateral ridges, referred to as dauer alae.
