Lecture 17 Flashcards
(11 cards)
_____ is a defect that arises from an intrinsically abnormal developmental process (i.e. genetic factors).
Malformation
______ is an abnormal form, shape, or position of a body part that results from mechanical forces.
Deformation
______ is a morphological defect that results from an interference with an originally normal developmental process; this interference is caused by what are called ______ (e.g. drugs or viruses.) It’s important to note that these defects cannot be inherited, but what can be is ______ to them.
Disruption
Teratogens
Susceptibility
A _____ is different than a syndrome, in that the anomalies associated with a syndrome have a known and identifiable cause.
Association
Rubenstein-Taybi syndrome is caused by a mutation of ______, an essential transcription factor.
CREB
Fetal Alcohol Syndrome is associated with craniofacial abnormalities and ____ ____ disease. The reason this syndrome has these associated abnormalities is because ____ ____ cells (those affected by the teratogen - alcohol) are involved in the development of nerves, facial bone and musculature, teeth dentin, and valves and aortic arch of the ____.
Congenital Heart disease
Neural Crest cells
Heart
Vitamin ____ deficiency impairs vision, repro, embryogenesis, and promotes _____. However, higher doses are severely teratogenic.
vitamin A
Oncogenesis
______, Vitamin ___ derivatives, activate developmental gene (including HOX genes) expression via nuclear hormone receptors.
Retinoids
Vitamin A
_______ syndrome type I in humans results in a white patch or spotting of ventral structures and is caused by a mutation in ____3 (a transcription factor). These patients are heterozygous for the mutation. Homozygotes have a more severe phenotype, including ______ (brain on the outside) and/or spina _____ as well as congenital heart defects.
Note: neural crest cells become ____, the cells that provide pigment.
Waardenburg syndrome
Pax3
Exencephaly
spina Bifida
Melanocytes
“Little Paxy Waardenburg had HETERO-hair coloration”
_____ acid can prevent neural tube defects (NTDs) in patients with ___3 mutations (the one that leads to Waardenburg type 1 syndrome.)
Folic acid (folate)
Pax3
____ genes encode proteins with a homeodomain(a helix-turn-helix structure) that binds gene regulators. The expression of these genes in tissues indicates anterior to posterior positioning of these tissues and corresponds to what?
HOX
The gene’s position on the chromosome (anterior gene –> begin expression in anterior tissues and continue all the way through posterior. More posterior genes begin their expression in more posterior tissues.) Keep in mind the overlap of expression. That is, in lumbar regions, cervical, thoracic, and lumbar HOX genes are expressed, while in the thoracic, only cervical and thoracic genes are expressed. Have an idea of what this means for tissue morphology should a particular HOX gene be nonfunctional.
