Abstract
τ-Crystallin is a taxon-specific structural protein found in eye lenses. We present here the cloning and sequencing of complete τ-crystallin cDNA from the embryonic lens ofCrocodylus palustris and establish it to be identical to the α-enolase gene from non-lenticular tissues. Quantitatively, the τ-crystallin was found to be the least abundant crystallin of the crocodilian embryonic lenses. Crocodile τ-crystallin cDNA was isolated by RT-PCR using primers designed from the only other reported sequence from duck and completed by 5′- and 3′-rapid amplification of cDNA ends (RACE) using crocodile gene specific primers designed in the study. The complete τ-crystallin cDNA of crocodile comprises 1305 bp long ORF and 92 and 409 bp long untranslated 5′- and 3′-ends respectively. Further, it was found to be identical to its putative counterpart enzyme α-enolase, from brain, heart and gonad, suggesting both to be the product of the same gene. The study thus provides the first report on cDNA sequence of τ-crystallin from a reptilian species and also re-confirms it to be an example of the phenomenon of gene sharing as was demonstrated earlier in the case of peking duck. Moreover, the gene lineage reconstruction analysis helps our understanding of the evolution of crocodilians and avian species.
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Abbreviations
- GAM:
-
Genital ridge-adrenal-metanephrosis complex
- ORF:
-
open reading frame
- RACE:
-
rapid amplification of cDNA ends
- UTR:
-
untranslated region
References
Aggarwal R K, Majumdar K, Lang J W and Singh L 1994 Generic affinities among crocodilians: as revealed by DNA fingerprinting using a Bkm-derived probe;Proc. Natl. Acad. Sci. USA 91 10601–10605
Altschul S F, Gish W, Miller W, Myers E W and Lipman D J 1990 Basic local alignment search tool;J. Mol. Biol. 215 403–410
Bloemendal H and deJong W W 1991 Lens proteins and their genes;Prog. Nucleic Acid Res. Mol. Biol. 41 259–280
Chiou S H, Chang W P and Chen C C 1989 Characterization and comparison of epsilon-crystallin and lactate dehydrogenases in the lenses of vertebrates and invertebrates;Biochem. Int. 18 1093–1100
Corpet F 1988 Multiple sequence alignment with hierarchical clustering;Nucleic Acids Res. 16 10881–10890
Felsenstein J 1994PHYLIP (Phylogeny Inference Package). Version 3.6. Department of Genetics, University of Washington, Seattle, USA
Ferguson M W J 1987 Post-laying stages of embryonic development for crocodilians; inWildlife management: Crocodiles and alligators 1987 (eds) G J W Webb, S C Manolis and P J Whitehead (Chipping Norton; Surrey Beatty) pp 427–444
Frohman M A, Dush M K and Martin G R 1988 Rapid production of full-length cDNAs from rare transcripts: amplification using a single gene-specific oligonucleotide primer;Proc. Natl. Acad. Sci. USA 85 8998–9002
Hendriks W J, Mulders W M, Bibby M A, Slingsby C, Bloemendal H and deJong W W 1988 Duck lens ɛ-crystallin and lactate dehydrogenase B4 are identical: a single gene product with two distinct functions;Proc. Natl. Acad. Sci. USA 85 7114–7118
Janke A and Arnason U 1997 The complete genome ofAlligator mississippiensis and the separation between recent archosauria (birds and crocodiles);Mol. Biol. Evol. 14 1266–1272
Kim R Y, Lietman T, Piatigorsky J and Wistow G J 1991 Structure and expression of the duck alpha-enolase/tau-crystallinencoding gene;Gene 103 193–200
Kraft H J, Voorter C E, Wintjes L, Lubsen N H and Schoenmakers J G 1994 The developmental expression of taxonspecific crystallins in the duck lens;Exp. Eye Res. 58 389–395
Lovtrup S 1985 On the classification of the taxon tetrapoda;Syst. Zool. 34 463–470
Mannen H and Li S S 1999 Molecular evidence for a clade of turtles;Mol. Phylogenet. Evol. 13 144–148
Mishra A K, Chandrashekhar R, Aggarwal R K and Sharma Y 2002 Crocodilian τ-crystallin: overexpression, purification and characterization;Protein Expres. Purif. (in press)
Rozen S and Skaletsky H J 1998 Primer3. Code available athttp://www.genome.wi.mit.edu/genome_software/other/primer3.html
Staple S O and deJong W W 1983 Lamprey 48 kDa lens protein represents a novel class of crystallins;FEBS Lett. 162 305–309
Tracy M R and Hedges S B 2000 Evolutionary history of the enolase gene family;Gene 259 129–138
Williams L A, Ding L, Horwitz J and Piatigorsky J 1985 τ-Crystallin from the turtle lens: purification and partial characterization;Exp. Eye Res. 40 741–749
Wistow G J and Piatigorsky J 1987 Recruitment of enzymes as lens structural proteins;Science 236 1554–1556
Wistow G J and Piatigorsky J 1988 Lens crystallins: evolution and expression of proteins for a highly specialized tissue;Annu. Rev. Biochem. 57 479–504
Wistow G J, Lietman T, Williams L A, Stapel S O, deJong W W, Horwitz J and Piatigorsky J 1988 τ-crystallin/α-enolase: one gene encodes both an enzyme and a lens structural protein;J. Cell Biol. 107 2729–2736
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Agrawal, R., Chandrashekhar, R., Mishra, A.K. et al. Cloning and sequencing of complete τ-crystallin cDNA from embryonic lens ofCrocodylus palustris . J Biosci 27, 251–259 (2002). https://doi.org/10.1007/BF02704914
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DOI: https://doi.org/10.1007/BF02704914