Patterns of localization and cytoskeletal association of two vegetally localized RNAs, Vg1 and Xcat-2.
In Xenopus, localization of a rare class of mRNAs during oogenesis is believed to initiate pattern formation in the early embryo. We have determined the pattern of RNA localization for one of these RNAs, Xcat-2, which encodes a putative RNA-binding protein related to Drosophila nanos (Mosquera, L., Forristall, C., Zhou, Y. and King, M. L. (1993) Development 117, 377-386). Xcat-2 is exclusively localized to the mitochondrial cloud in stage I oocytes, moves with this body into the vegetal cortex during stage II and, later, partitions into islands consistent with it being a component of the germ plasm. As previously shown, Vg1 is not localized to the vegetal cortex until stage IV and distributes to all vegetal blastomeres during development. We found a direct correlation between the localized condition of these RNAs and their recovery in a detergent-insoluble fraction. We present evidence suggesting that differential RNA binding to a cytoskeletal component(s) in the vegetal cortex determines the pattern of inheritance for that RNA in the embryo.
Forristall
C
C
Department of Cell Biology and Anatomy (R-124), University of Miami School of Medicine, FL 33101.
Pondel
M
M
Chen
L
L
King
M L
ML
D000818:Animals; D003599:Cytoskeleton / Q000235:genetics*; D015870:Gene Expression; D005796:Genes; D017403:In Situ Hybridization; D008928:Mitochondria / Q000502:physiology; D009865:Oocytes / Q000502:physiology; D009866:Oogenesis / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis*; D014981:Xenopus / Q000196:embryology / Q000235:genetics*
D012333:RNA, Messenger