Nevertheless, because sand dollars (like most marine invertebrates) have external fertilization and no parental care, opportunities for non-genetic paternal contributions to embryonic and larval development are limited to substances or organelles in the sperm itself (such as the
centriole) and paternal imprinting {via, e.g., methylation patterns; see, e.g., McBirney et al., 2017), of which there have been no reports to date in echinoids (sand dollars and urchins).
To date, 19 genes (MCPH1-19) have been linked to MCPH (Abdel-Hamid et al., 2016) that encode proteins involved in cell cycle regulation, DNA damage response,
centriole duplication, neurogenesis and spindle pole organization and orientation (Bond et al., 2002; Faheem et al., 2015).
Rare patterns were consisted of 49 (0.49%) midbody, 29 (0.29%)
centriole, 20 (0.20%) spindle fibers, 21 (0.21%) anti-golgi, 37 (0.37%) anti-actin, 3 (0.03%) rod and rings, and 9 (0.09%) PCNA (proliferating cell nuclear antigen)-like (Table 1).
Centrosomes contain two
centrioles, the mother
centriole and a younger newly duplicated daughter
centriole (Vorobjev & Chentsov 1982, Azimzadeh & Marshall 2010).
Normark, "Evolutionary problems in centrosome and
centriole biology," Journal of Evolutionary Biology, vol.
Gonzalez et al., "Microcephaly proteins Wdr62 and Aspm define a mother
centriole complex regulating
centriole biogenesis, apical complex, and cell fate," Neuron, vol.
Their topics include post-translational modifications of tubulin and cilia, the central apparatus of cilia and eukaryotic flagella, transition zone migration: a mechanism for cytoplasmic ciliogenesis and postaxonemal
centriole elongation, primary cilia and mammalian hedgehog signaling, G-protein-coupled receptor signaling in cilia, ciliary mechanisms of cyst formation in polycystic kidney disease, sperm sensory signaling, cilia and ciliopathies in congenital heart disease, photoreceptor cilia and retinal ciliopathies, and the evolution of cilia.
CEP135 encodes a centrosomal protein that acts as a scaffolding protein during early
centriole biogenesis (Kim et al.
The research findings described in this media release can be found in the 17 December online issue of Neuron, Cell Press under the title, "Katanin p80 Regulates Human Cortical Development by Limiting
Centriole and Cilia Number" by Wen F.
POC1B is involved in the early steps of
centriole duplication and the later steps of
centriole length control [44, 45].
Pattern group Pattern Nuclear envelope Smooth nuclear envelope (membrane) Punctate nuclear envelope Homogeneous pattern Large speckled Coarse speckled Fine speckled Fine grainy Scl-70-like Nuclear Pleomorphic speckled (i.e., PCNA) Centromere Multiple nuclear dots Coiled bodies (few nuclear dots) Dense fine speckled Isolated metaphase chromosomes Homogeneous nucleolar Nucleolar Clumpy nucleolar Punctate nucleolar
Centriole (centrosome) Mitotic spindle apparatus Spindle pole (NuMa) (MSA-1) (HSeg5) Spindle fiber Midbody (MSA-2) CENP-F (MSA-3) Diffuse Fine speckled Mitochondrial Cytoplasmic Discrete dots: GW bodies, endosomes, lysosomes Golgi complex Intercellular contact proteins Fibers and cytoskeleton Rods and rings Negative Table 7: Automated digital ANA reading systems.