共查询到20条相似文献,搜索用时 15 毫秒
1.
Vera Gamulin Alexander Skorokhod Vadim Kavsan Isabel M. Müller Werner E. G. Müller 《Journal of molecular evolution》1997,44(3):242-252
We have analyzed the gene that encodes receptor tyrosine kinase (RTK) from the marine sponge Geodia cydonium, which belongs to the most ancient and simple metazoan groups, the Porifera. RTKs are enzymes found only in metazoa. The sponge
gene contains two introns in the extracellular part of the protein. However, the rest of the protein (transmembrane and intracellular
part), including the tyrosine kinase (TK)-domain, is encoded by a single exon. In contrast, all TK genes, so far known only
from higher animals (vertebrates), contain several introns especially in the TK-domain. The TK-domain of G. cydonium shows similarity with numerous members of receptor as well as nonreceptor TKs. Phylogenetic analysis of the sponge TK-domain
indicates that this enzyme branched off first from the common tree of metazoan TK proteins. Consequently, we assume that introns,
found in the TK-domains of genes from higher animals, were inserted into these genes after splitting off the sponge taxa from
other metazoan organisms (over 600 million years ago). Our results support the view that ancient genes were not ``in pieces.'
Received: 8 August 1996 / Accepted: 4 November 1996 相似文献
2.
3.
Cells from metazoan organisms are eliminated in a variety of physiological and pathophysiological processes by apoptosis.
In this report, we describe the cloning and characterization of molecules from the marine sponges Geodia cydonium and Suberites domuncula, whose domains show a high similarity to those that are found in molecules of the vertebrate Bcl-2 superfamily and of the
death receptors. The Bcl-2 proteins contain up to four Bcl-2 homology regions (BH). Two Bcl-2-related molecules have been
identified from sponges that are provided with two of those regions, BH1 and BH2, and are termed Bcl-2 homology proteins (BHP).
The G. cydonium molecule, BHP1_GC, has a putative size of 28,164, while the related sequence from S. domuncula, BHP1_SD, has a M
r
of 24,187. Phylogenetic analyses of the entire two sponge BHPs revealed a high similarity to members of the mammalian Bcl-2
superfamilies and to the Caenorhabditis elegans Ced-9. When the two domains, BH1 and BH2, are analyzed separately, again the highest similarity was found to the members
of the Bcl-2 superfamily, but a clearly lower relationship to the C. elegans BH1 and BH2 domains in Ced-9. In unrooted phylogenetic trees the sponge BH1 and BH2 are grouped among the mammalian sequences
and are only distantly related to the C. elegans BH domains. The analysis of the gene structure of the G. cydonium BHP showed that the single intron present is located within the BH2 domain at the same position as in C. elegans and rat Bcl-xL. In addition, a sponge molecule comprising two death domains has been characterized from G. cydonium. The two death domains of the potential proapoptotic molecule GC_DD2, M
r
24,970, share a high similarity with the Fas-FADD/MORT1 domains. A death domain-containing molecule has not been identified
in the C. elegans genome. The phylogenetic analysis revealed that the sponge domain originated from an ankyrin building block from which the
mammalian Fas-FADD/MORT1 evolved. It is suggested that the apoptotic pathways that involve members of the Bcl-2 superfamily
and of the death receptors are already present in the lowest metazoan phylum, the Porifera.
Received: 27 July 1999 / Accepted: 28 December 1999 相似文献
4.
Michael Kruse Vera Gamulin Helena Cetkovic Zeev Pancer Isabel M. Müller Werner E. G. Müller 《Journal of molecular evolution》1996,43(4):374-383
Protein kinases C (PKCs) comprise closely related Ser/Thr kinases, ubiquitously present in animal tissues; they respond to
second messengers, e.g., Ca2+ and/or diacylglycerol, to express their activities. Two PKCs have been sequenced from Geodia cydonium, a member of the lowest multicellular animals, the sponges (Porifera). One sponge G. cydonium PKC, GCPKC1, belongs to the ``novel' (Ca2+-independent) PKC (nPKC) subfamily while the second one, GCPKC2, has the hallmarks of the ``conventional' (Ca2+-dependent) PKC (cPKC) subfamily. The alignment of the Ser/Thr catalytic kinase domains, of the predicted aa sequences for
these cDNAs with respective segments from previously reported sequences, revealed highest homology to PKCs from animals but
also distant relationships to Ser/Thr kinases from protozoa, plants, and bacteria. However, a comparison of the complete structures
of the sponge PKCs, which are—already—identical to those of nPKCs and cPKCs from higher metazoa, with the structures of protozoan,
plant, and bacterial Ser/Thr kinases indicates that the metazoan PKCs have to be distinguished from the nonmetazoan enzymes.
These data indicate that metazoan PKCs have a universal common ancestor which they share with the nonmetazoan Ser/Thr kinases
with respect to the kinase domain, but they differ from them in overall structural composition.
Received: 10 January 1996 / Accepted: 12 March 1996 相似文献
5.
Adell T Gamulin V Perović-Ottstadt S Wiens M Korzhev M Müller IM Müller WE 《Journal of molecular evolution》2004,59(1):41-50
Until recently the positioning of the sponges (phylum Porifera) within the metazoan systematics was hampered by the lack of molecular evidence for the existence of junctional structures in the surface cell layers. In this study two genes related to the tight junctions are characterized from the demosponge Suberites domuncula: tetraspanin (SDTM4SF), a cell surface receptor, and MAGI (SDMAGI), a MAGUK (membrane-associated guanylate kinase homologue) protein. Especially the MAGI protein is known in other metazoan animal phyla to exist exclusively in tight junctions. The characteristic domains of MAGI proteins (six PDZ domains, two WW domains, and a truncated guanylate kinase motif) are conserved in the sponge protein. The functional analysis of SDMAGI done by in situ hybridization shows its expression in the surface epithelial layers (exopinacoderm and endopinacoderm). Northern blot studies reveal that expression of SDMAGI and SDTM4SF increases after formation of the pinacoderm layer in the animals as well as in primmorphs. These results support earlier notions that sponges contain junctional structures. We conclude that sponges contain epithelia whose cells are organized by cell junctions.The sequence from Suberites domuncula reported here, the protein membrane-associated guanylate kinase with an inverted arrangement (MAGI), is deposited in the EMBL/GenBank database under accession number AJ580406. 相似文献
6.
Barbara Blumbach Bärbel Diehl-Seifert Jürgen Seack Renate Steffen Isabel M. Müller W. E. G. Müller 《Immunogenetics》1999,49(9):751-763
A cDNA encoding a receptor tyrosine kinase (RTK) was previously cloned and expressed from the marine sponge (Porifera) Geodia cydonium. In addition to the two intracellular regions characteristic for RTKs, two immunoglobulin (Ig)-like domains are found in
the extracellular part of the sponge RTK. In the present study it is shown that no further Ig-like domain is present in the
upstream region of the cDNA as well as of the gene hitherto known from the sponge RTK. Two different full-length cDNAs have
been isolated and characterized in the present study, which possess two Ig-like domains, one transmembrane segment, and only
a short intracellular part, without a TK domain. The two deduced polypeptides were preliminarily termed sponge adhesion molecules
(SAM). The longer form of the SAM, GCSAML, encodes a deduced aa sequence, GCSAML, which comprises in the open reading frame 505 amino acids (aa) and has a calculated
M
r of 53911. The short form, GCSAMS, has 313 aa residues and an M
r of 33987. The two Ig-like domains in GCSAML and GCSAMS are highly similar to the corresponding Ig-like domains in the RTKs
from G. cydonium; the substitutions on both the aa and nt level are restricted to a few sites. Phylogenetic analyses revealed that the Ig-like
domain 1 is similar to the human Ig lambda chain variable region, while the Ig-like domain 2 is related more closely to the
human Ig heavy chain variable region. Transplantation experiments (autografting) were performed to demonstrate that the level
of expression of the two new genes, GCSAML and GCSAMS, is upregulated during the self/self fusion process. Immunohistochemical analyses using antibodies raised against the two
Ig-like domains demonstrate a strong expression in the fusion zone between graft and host. This finding has been supported
by northern blotting experiments that revealed that especially GCSAML is strongly upregulated after autografting (up to 12-fold); the expression of GCSAMS reaches a value of 5-fold if compared with the controls. The results presented here demonstrate that the expression of the
new molecules described, comprising two Ig-like domains, is upregulated during the process of autograft fusion.
Received: 17 November 1998 / Revised: 15 March 1999 相似文献
7.
Müller WE Wimmer W Schatton W Böhm M Batel R Filic Z 《Marine biotechnology (New York, N.Y.)》1999,1(6):569-579
Among Metazoa, sponges (phylum Porifera) are the richest source for different bioactive compounds. The availability of the
raw material is, however, restricted. To obtain enough of the bioactive compounds for application in human therapy, sponges
have to be cultured in in vitro systems. One technique for the establishment of a long-term cell culture from sponges has
recently been elaborated. Here, we present a procedure to cultivate tissue samples from sponges in an open system. The species
Geodia cydonium, which produces bioactive compounds, has been selected. Tissue samples of approximately 10 g were attached to the bottoms
of cultivation trays. After 2 to 3 days, the tissue samples formed a robust contact with the metal support. Subsequently,
sets of trays, called tray batteries, either remained in huge aquaria at the Center for Marine Research or were transferred
to the vicinity of a fish and mussel farm. The growth rates of the samples remained unchanged within the first month; however,
after 3 and 6 months, they increased to 147% and 189%, respectively. In parallel, extracts were prepared from the tissue samples
and tested for cytotoxicity in a mouse lymphoma cell assay system. Extracts from cultured tissue initially had a low inhibitory
potency; however, after cultivation for 3 or 6 months, values comparable to those of extracts from sponges taken from the
biotope were found. In addition, a molecular marker was applied to document the response (health state) of the tissue and
the identity of the material in culture. The CD63 molecule was chosen because the expression of this molecule in mammalian
systems changes with the age of the animals. The corresponding complementary DNA was isolated from Geodia cydonium. With this probe, the level of expression in cultured tissue samples decreased immediately after starting cultivation; after
a cultivation period of 6 months, however, values were similar to those found in controls. These data show that sponge species
that produce bioactive compounds can be cultivated in open systems, in which they retain their potency to produce bioactive
compounds as well as their health state.
Received September 16, 1998; accepted June 18, 1999 相似文献
8.
Juan Ausiö Manfred L. J. Van Veghel Raquel Gomez Daniel Barreda 《Journal of molecular evolution》1997,45(1):91-96
We have isolated and characterized for the first time, the SNBPs from an organism (Neofibularia nolitangere) of the phylum Porifera (Sponges). We have shown that these proteins consist of histones which, as expected, exhibit an amino
acid composition very similar to that of other eukaryotic histones. The finding of histones in the sperm of these primitive
organisms provides support to the notion that histones (SNBPs of the histone, H, type) were the proteins present at the onset
of SNBP evolution. In contrast, a discrete number of alternative SNBP types (protamine-like, PL; protamine, P, types) seem
to have appeared later on in the course of evolution and are found in both protostomes and deuterostomes, most likely as a
result of processes of parallel evolution.
Received: 5 March 1997 / Accepted: 6 March 1997 相似文献
9.
Müller WE Schlossmacher U Eckert C Krasko A Boreiko A Ushijima H Wolf SE Tremel W Müller IM Schröder HC 《European journal of cell biology》2007,86(8):473-487
The skeleton of the siliceous sponges (Porifera: Hexactinellida and Demospongiae) is supported by spicules composed of bio-silica. In the axial canals of megascleres, harboring the axial filaments, three isoforms of the enzyme silicatein (-alpha, -beta and -gamma) have been identified until now, using the demosponges Tethya aurantium and Suberites domuncula. Here we describe the composition of the proteinaceous components of the axial filament from small spicules, the microscleres, in the demosponge Geodia cydonium that possesses megascleres and microscleres. The morphology of the different spicule types is described. Also in G. cydonium the synthesis of the spicules starts intracellularly and they are subsequently extruded to the extracellular space. In contrast to the composition of the silicateins in the megascleres (isoforms: -alpha, -beta and -gamma), the axial filaments of the microscleres contain only one form of silicatein, termed silicatein-alpha/beta, with a size of 25kDa. Silicatein-alpha/beta undergoes three phosphorylation steps. The gene encoding silicatein-alpha/beta was identified and found to comprise the same characteristic sites, described previously for silicateins-alpha or -beta. It is hypothesized, that the different composition of the axial filaments, with respect to silicateins, contributes to the morphology of the different types of spicules. 相似文献
10.
Schröder HC Natalio F Shukoor I Tremel W Schlossmacher U Wang X Müller WE 《Journal of structural biology》2007,159(3):325-334
Recently it has been discovered that the formation of the siliceous spicules of Demospongiae proceeds enzymatically (via silicatein) and occurs matrix guided (on galectin strings). In addition, it could be demonstrated that silicatein, if immobilized onto inorganic surfaces, provides the template for the synthesis of biosilica. In order to understand the formation of spicules in the intact organism, detailed studies with primmorphs from Suberites domuncula have been performed. The demosponge spicules are formed from several silica lamellae which are concentrically arranged around the axial canal, harboring the axial filament composed of silicatein. Now we show that the appositional growth of the spicules in radial and longitudinal direction proceeds in the extracellular space along hollow cylinders; their surfaces are formed by silicatein. The extracellularly located spicules are surrounded by sclerocytes which are filled with both electron-dense and electron-poor vesicles; energy dispersive X-ray analysis/scanning electron microscopical studies revealed that the electron-dense vesicles are filled of silicon/silica and therefore termed silicasomes. The release of the content of the silicasomes into the hollow cylinder suggests that the newly formed silica lamella originate there; in addition the data are compatible with the view that the silicatein molecules, attached at the centripetal and centrifugal surfaces, mediate biosilica formation. In a chemical/biomimetical approach silicatein is linked onto the organic material-free spicules after their functionalization with aminopropyltriethoxysilane [amino groups]-poly(acetoxime methacrylate) [reactive ester polymer]-N(epsilon)-benzyloxycarbonyl L-lysine tert-butyl ester-Ni(II); finally His-tagged silicatein is immobilized. The matrix-bound enzyme synthesized a new biosilica lamella. These bioinspired findings are considered as the basis for a technical use/application/utilization of hollow cylinders formed by matrix-guided silicatein molecules for the biocatalytic synthesis of nanostructured tubes. 相似文献
11.
Characterization of the Hydra Lamin and Its Gene: A Molecular Phylogeny of Metazoan Lamins 总被引:4,自引:0,他引:4
Andreas Erber Dieter Riemer Helmut Hofemeister Marc Bovenschulte Reimer Stick Georgia Panopoulou Hans Lehrach Klaus Weber 《Journal of molecular evolution》1999,49(2):260-271
We report sequences for nuclear lamins from the teleost fish Danio and six invertebrates. These include two cnidarians (Hydra and Tealia), one priapulid, two echinoderms, and the cephalochordate Branchiostoma. Combining these results with earlier data on Drosophila, Caenorhabditis elegans, and various vertebrates, the following conclusions on lamin evolution can be drawn. First, all invertebrate lamins resemble
in size the vertebrate B-type lamin. Second, all lamins described previously for amphibia, birds and mammals as well as the
first lamin of a fish, characterized here, show a cluster of 7 to 12 acidic residues in the tail domain. Since this acidic
cluster is absent from all invertebrate lamins including that of the cephalochordate Branchiostoma, it was acquired with the vertebrate lineage. The larger A-type lamin of differentiated cells must have arisen subsequently
by gene duplication and insertion of an extra exon. This extra exon of the vertebrate A-lamins is the only major change in
domain organization in metazoan lamin evolution. Third, the three introns of the Hydra and Priapulus genes correspond in position to the last three introns of vertebrate B-type lamin genes. Thus the entirely different gene
organization of the C. elegans and Drosophila Dmo genes seems to reflect evolutionary drift, which probably also accounts for the fact that C. elegans has the most diverse lamin sequence. Finally we discuss the possibility that two lamin types, a constitutively expressed
one and a developmentally regulated one, arose independently on the arthropod and vertebrate lineages.
Received: 4 February 1999 / Accepted: 1 April 1999 相似文献
12.
The emergence of jawed vertebrates was predicated on the appearance of several innovations, including tooth formation. The
development of teeth requires the participation of several specialized genes, in particular, those necessary for the formation
of hard tissues—dentin, enamel, and cementum. Some vertebrates, most conspicuously birds, secondarily lost the tooth-forming
ability. To determine the fate of some of the tooth-forming genes in the birds, we tested a domestic fowl cDNA library for
the expression of the dentin matrix protein 1 (DMP1) gene. The library was prepared from the poly(A+) RNA isolated from the jaws of 11- to 13-day-old embryos and the testing was carried out by the polymerase chain reaction
with degenerate primers designed on the basis of the available mammalian and reptile sequences. A chicken homologue of the
DMP1 gene identified by this approach was shown to be expressed in the jaws and long bones, the same two tissues as in mammals.
The chicken DMP1 gene has an exon/intron organization similar to that of its mammalian and reptile counterparts. The chicken gene contains
three short highly conserved segments, the rest of the gene being poorly alignable or not alignable with its mammalian or
reptilian homologues. The distribution of similarities and dissimilarities along the gene is indicative of a mode of evolution
in which only short segments are kept constant, while the rest of the gene is relatively free to vary as long as the proportion
of certain amino acid residues is retained in the encoded polypeptide. The DMP1 gene may have been retained in birds because of its involvement in bone formation.
Received: 5 April 1999 / Accepted: 9 August 1999 相似文献
13.
Biglycan and decorin are two members of a family of small extracellular matrix proteoglycans characterized by the presence
of 10 leucine-rich repeats and one or two attachment sites for glucosaminoglycans. Both have thus far been described only
from tetrapod species, mainly mammals. Because the extracellular matrix has played an important part in the evolution of Metazoa,
the phylogeny of its components is of considerable interest. In this study, biglycan-like (BGL) cDNA sequences have been obtained
from two teleost (Oreochromis cichlid and zebrafish) and two lamprey species. The analysis of the sequences suggests that, like tetrapods, the lampreys
possess two types of proteoglycans, both of which are biglycan-like; decorin-like proteoglycans could not be identified in
these species. The genes specifying these two types apparently arose by duplication in the lamprey lineage after its divergence
from gnathostomes. The two teleost species possess a BGL proteoglycan and a bona fide decorin. The BGL proteoglycan is highly
divergent from the tetrapod biglycan and related to the BGL proteoglycans of the lamprey. Hence, although the duplication
generating the ancestors of biglycan and decorin genes occurred after the divergence of agnathans but before the emergence
of teleosts, only decorin acquired its characteristic properties in the bony fishes. The BGL gene presumably turned into a typical biglycan only in the tetrapod lineages. The presumed acquisitions of new functions
appear to have been accompanied by changes in the evolutionary rate.
Received: 13 April 2000 / Accepted: 4 July 2000 相似文献
14.
Böhm M Schröder HC Müller IM Müller WE Gamulin V 《Biology of the cell / under the auspices of the European Cell Biology Organization》2000,92(2):95-104
Our recent data suggest that during auto- and allograft recognition in sponges (Porifera), cytokines are differentially expressed. Since the mitogen-activated protein kinase (MAPK) signal transduction modulates the synthesis and release of cytokines, we intended to identify one key molecule of this pathway. Therefore, a cDNA from the marine sponge Suberites domuncula encoding the MAPK was isolated and analyzed. Its encoded protein is 366 amino acids long (calculated Mr 42 209), has a TGY dual phosphorylation motif in protein kinase subdomain VIII and displays highest overall similarity to the mammalian p38 stress activated protein kinase (SAPK2), one subfamily of MAPKs. The sponge protein was therefore termed p38_SD. The overall homology (identity and similarity) between p38_SD and human p38alpha (CSBP2) kinase is 82%. One feature of the sponge kinase is the absence of threonine at position 106. In human p38alpha MAPK this residue is involved in the interaction with the specific pyridinyl-imidazole inhibitor; T106 is replaced in p38_SD by methionine. Inhibition studies with the respective inhibitor SB 203580 showed that it had no effect on the phosphorylation of the p38 substrate myelin basic protein. A stress responsive kinase Krs_SD similar to mammalian Ste20 kinases, upstream regulators of p38, had already previously been found in S. domuncula. The S. domuncula p38 MAPK is phosphorylated after treatment of the animal in hypertonic medium. In contrast, exposure of cells to hydrogen peroxide, heat shock and ultraviolet light does not cause any phosphorylation of p38. It is concluded that sponges, the oldest and most simple multicellular animals, utilize the conserved p38 MAPK signaling pathway, known to be involved in stress and immune (inflammatory) responses in higher animals. 相似文献
15.
We have investigated the phylogenetic relationships of monotremes and marsupials using nucleotide sequence data from the
neurotrophins; nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3). The study included
species representing monotremes, Australasian marsupials and placentals, as well as species representing birds, reptiles,
and fish. PCR was used to amplify fragments encoding parts of the neurotrophin genes from echidna, platypus, and eight marsupials
from four different orders. Phylogenetic trees were generated using parsimony analysis, and support for the different tree
structures was evaluated by bootstrapping. The analysis was performed with NGF, BDNF, or NT-3 sequence data used individually
as well as with the three neurotrophins in a combined matrix, thereby simultaneously considering phylogenetic information
from three separate genes. The results showed that the monotreme neurotrophin sequences associate to either therian or bird
neurotrophin sequences and suggests that the monotremes are not necessarily related closer to therians than to birds. Furthermore,
the results confirmed the present classification of four Australasian marsupial orders based on morphological characters,
and suggested a phylogenetic relationship where Dasyuromorphia is related closest to Peramelemorphia followed by Notoryctemorphia
and Diprotodontia. These studies show that sequence data from neurotrophins are well suited for phylogenetic analysis of mammals
and that neurotrophins can resolve basal relationships in the evolutionary tree.
Received: 27 January 1997 / Accepted: 20 March 1997 相似文献
16.
17.
Wallis M 《Journal of molecular evolution》2000,50(5):465-473
Previous studies have shown that pituitary growth hormone displays an episodic pattern of evolution, with a slow underlying
evolutionary rate and occasional sustained bursts of rapid change. The present study establishes that pituitary prolactin
shows a similar pattern. During much of tetrapod evolution the sequence of prolactin has been strongly conserved, showing
a slow basal rate of change (approx 0.27 × 109 substitutions/amino acid site/year). This rate has increased substantially (∼12- to 38-fold) on at least four occasions during
eutherian evolution, during the evolution of primates, artiodactyls, rodents, and elephants. That these increases are real
and not a consequence of inadvertant comparison of paralogous genes is shown (for at least the first three groups) by the
fact that they are confined to mature protein coding sequence and not apparent in sequences coding for signal peptides or
when synonymous substitutions are examined. Sequences of teleost prolactins differ markedly from those of tetrapods and lungfish,
but during the course of teleost evolution the rate of change of prolactin has been less variable than that of growth hormone.
It is concluded that the evolutionary pattern seen for prolactin shows long periods of near-stasis interrupted by occasional
bursts of rapid change, resembling the pattern seen for growth hormone in general but not in detail. The most likely basis
for these bursts appears to be adaptive evolution though the biological changes involved are relatively small.
Received: 31 August 1999 / Accepted: 9 February 2000 相似文献
18.
Molecular Evolution of the Myeloperoxidase Family 总被引:4,自引:0,他引:4
Animal myeloperoxidase and its relatives constitute a diverse protein family, which includes myeloperoxidase, eosinophil
peroxidase, thyroid peroxidase, salivary peroxidase, lactoperoxidase, ovoperoxidase, peroxidasin, peroxinectin, cyclooxygenase,
and others. The members of this protein family share a catalytic domain of about 500 amino acid residues in length, although
some members have distinctive mosaic structures. To investigate the evolution of the protein family, we performed a comparative
analysis of its members, using the amino acid sequences and the coordinate data available today. The results obtained in this
study are as follows: (1) 60 amino acid sequences belonging to this family were collected by database searching. We found
a new member of the myeloperoxidase family derived from a bacterium. This is the first report of a bacterial member of this
family. (2) An unrooted phylogenetic tree of the family was constructed according to the alignment. Considering the branching
pattern in the obtained phylogenetic tree, together with the mosaic features in the primary structures, 60 members of the
myeloperoxidase family were classified into 16 subfamilies. (3) We found two molecular features that distinguish cyclooxygenase
from the other members of the protein family. (4) Several structurally deviated segments were identified by a structural comparison
between cyclooxygenase and myeloperoxidase. Some of the segments seemed to be associated with the functional and/or structural
differences between the enzymes.
Received: 25 January 2000 / Accepted: 19 July 2000 相似文献
19.
Nuria Saperas Manel Chiva David C. Pfeiffer Harold E. Kasinsky Juan Ausió 《Journal of molecular evolution》1997,44(4):422-431
We have characterized for the first time SNBPs from the hagfish Eptatratus stouti (Myxini) and the lamprey Lampetra tridentatus (Cephalaspidomorphi) and have found that histones are the major protein components of the sperm of these agnathans. We have
also conducted a systematic analysis of SNBPs from different groups of chondrichthyan fishes, including the skate Raja rhina and seven species of sharks. Together with our previous data showing the sporadic nature of SNBP evolution in bony fish (Saperas,
N., Ausio, J., Lloris, D. and Chiva, M. [1994] J. Mol. Evol. 39: 282–295), the present study provides a unique insight into the overall evolutionary complexity and variability of the
nuclear sperm proteins of fishes. It would appear that despite the discontinuous evolution of these proteins, the macroevolutionary
pattern of histone (H type) → protamine-like (PL type) → protamine (P type) has been conserved in fish evolution, as it has
in the evolution of other Deuterostomes.
Received: 11 June 1996 / Accepted: 6 August 1996 相似文献
20.
The Molecular Evolution of the Vertebrate Trypsinogens 总被引:1,自引:0,他引:1
We expand the already large number of known trypsinogen nucleotide and amino acid sequences by presenting additional trypsinogen
sequences from the tunicate (Boltenia villosa), the lamprey (Petromyzon marinus), the pufferfish (Fugu rubripes), and the frog (Xenopus laevis). The current array of known trypsinogen sequences now spans the entire vertebrate phylogeny. Phylogenetic analysis is made
difficult by the presence of multiple isozymes within species and rates of evolution that vary highly between both species
and isozymes. We nevertheless present a Fitch-Margoliash phylogeny constructed from pairwise distances. We employ this phylogeny
as a vehicle for speculation on the evolution of the trypsinogen gene family as well as the general modes of evolution of
multigene families. Unique attributes of the lamprey and tunicate trypsinogens are noted.
Received: 12 July 1997 相似文献