A major role for zygotic hunchback in patterning the Nasonia embryo.
Developmental genetic analysis has shown that embryos of the parasitoid wasp Nasonia vitripennis depend more on zygotic gene products to direct axial patterning than do Drosophila embryos. In Drosophila, anterior axial patterning is largely established by bicoid, a rapidly evolving maternal-effect gene, working with hunchback, which is expressed both maternally and zygotically. Here, we focus on a comparative analysis of Nasonia hunchback function and expression. We find that a lesion in Nasonia hunchback is responsible for the severe zygotic headless mutant phenotype, in which most head structures and the thorax are deleted, as are the three most posterior abdominal segments. This defines a major role for zygotic Nasonia hunchback in anterior patterning, more extensive than the functions described for hunchback in Drosophila or Tribolium. Despite the major zygotic role of Nasonia hunchback, we find that it is strongly expressed maternally, as well as zygotically. Nasonia Hunchback embryonic expression appears to be generally conserved; however, the mRNA expression differs from that of Drosophila hunchback in the early blastoderm. We also find that the maternal hunchback message decays at an earlier developmental stage in Nasonia than in Drosophila, which could reduce the relative influence of maternal products in Nasonia embryos. Finally, we extend the comparisons of Nasonia and Drosophila hunchback mutant phenotypes, and propose that the more severe Nasonia hunchback mutant phenotype may be a consequence of differences in functionally overlapping regulatory circuitry.
Pultz
Mary Anne
MA
Department of Biology, Western Washington University, Bellingham, WA 98225, USA. pultz@biol.wwu.edu
Westendorf
Lori
L
Gale
Samuel D
SD
Hawkins
Kyle
K
Lynch
Jeremy
J
Pitt
Jason N
JN
Reeves
Nick L
NL
Yao
Jennifer C Y
JC
Small
Stephen
S
Desplan
Claude
C
Leaf
David S
DS
D000818:Animals; D001483:Base Sequence; D019521:Body Patterning; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D008040:Genetic Linkage; D024002:HMGB Proteins / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D023121:RNA, Messenger, Stored / Q000378:metabolism; D016415:Sequence Alignment; D051820:TCF Transcription Factors; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014863:Wasps / Q000033:anatomy & histology / Q000196:embryology
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D024002:HMGB Proteins; D019476:Insect Proteins; D023121:RNA, Messenger, Stored; D051820:TCF Transcription Factors; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors; C061245:hb protein, Drosophila