GAD isoforms exhibit distinct spatiotemporal expression patterns in the developing mouse lens: correlation with Dlx2 and Dlx5.
Gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter of the adult nervous system and its biosynthetic enzyme glutamic acid decarboxylase (GAD) are abundantly expressed in the embryonic nervous system and are involved in the modulation of cell proliferation, migration, and differentiation. Here we describe for the first time the expression of GABA and embryonic and adult GAD isoforms in the developing mouse lens. We show that the GAD isoforms are sequentially induced with specific spatiotemporal profiles: GAD65 and embryonic GAD isoforms prevail in primary fibers, while GAD67 is the predominant GAD expressed in the postnatal secondary fibers. This pattern correlates well with the expression of Dlx2 and Dlx5, known as upstream regulators of GAD. GABA and GAD are most abundant at the tips of elongating fibers and are absent from organelle-free cells, suggesting their involvement is primarily in shaping of the cytoskeleton during fiber elongation stages.
Kwakowsky
Andrea
A
Department of Gene Technology and Developmental Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
Schwirtlich
Marija
M
Zhang
Qi
Q
Eisenstat
David D
DD
Erdélyi
Ferenc
F
Baranyi
Mária
M
Katarova
Zoya D
ZD
Szabó
Gábor
G
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005968:Glutamate Decarboxylase / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D007527:Isoenzymes / Q000235:genetics; D007908:Lens, Crystalline / Q000196:embryology* / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008954:Models, Biological; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D017931:DNA Primers; C088334:Distal-less homeobox proteins; C501120:Dlx5 protein, mouse; D018398:Homeodomain Proteins; D007527:Isoenzymes; D012333:RNA, Messenger; D014157:Transcription Factors; D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1; C401141:glutamate decarboxylase 2