An accessory protein to this complex, ZRSR2, is mutated in some cases of myelodysplastic (“MY-eh-loh-diss-PLASS-tick”) syndrome. For 10 points each:
[10h] Name this complex, first described by Woan-Yuh Tarn and Joan Steitz, that includes U4atac (“U-four-ah-tack”) and U6atac (“U-six-ah-tack”). This complex binds to regions with AT-AC or GT-AG sites that unusually lack a polypyrimidine (“POH-lee-pir-IH-mih-deen”) tract.
ANSWER: minor spliceosome [accept U12-dependent spliceosome; prompt on spliceosome; prompt on descriptions of an alternate splicing complex or similar]
[10e] The minor spliceosome is ubiquitously expressed, but its mutations mostly affect the nervous system. For instance, U11 mutations cause a dwarfism named for this birth defect also linked to maternal Zika virus infections.
ANSWER: microcephaly [accept microcephalic osteodysplastic primordial dwarfism; accept descriptions like “having a small head”; prompt on MOPD1]
[10m] Microcephaly-causing U11 mutations deplete these cells’ radial, Bergmann, and Müller types by forcing them to undergo neurogenesis instead of replicating or differentiating into other types of these cells.
ANSWER: glia [or radial glial cells; or neuroglia; accept Müller glia; accept Bergmann glia]
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