Genji Matsuda

Darwinian evolution in the genealogy of haemoglobin.

Frequencies of mutations between reconstructed ancestor and descendant sequences of codons for metazoan globin chains show that natural selection guided protein evolution. Mutations which improved haemoglobin function were accepted at an accelerated rate in the first vertebrates. Rates decelerated after functional opportunities had been exploited.

The phylogeny of human globin genes investigated by the maximum parsimony method

Gene phylogenetic trees were constructed by the maximum parsimony method for various sets of ninety six globin chain amino acid sequences spanning plant and animal kingdoms. The method, executed by several computer programs, constructed ancestor and descendant globin messengers on tree topologies which required the least number of nucleotide replacements to account for the evolution of the globins. The human myoglobin-hemoglobin divergence was traced to a gene duplication which occurred either in the first vertebrates or earlier yet in the common ancestor of chordates and annelids, the alpha-beta divergence to a gene duplication in the common ancestor of teleosts and tetrapods, the gamma divergence from typical beta chains to a gene duplication in basal therian mammals, and the delta separation from beta to a duplication in the basal catarrhine primates. Evidence was provided by the globin phylogenies for the hominoid affinities of the gibbon and the close phyletic relationship of the African apes to man. Over the period of teleos-tetrapod divergence the globin messengers evolved at an average rate of 18.5 nucleotide replacements per 100 codons per 108 years, a faster rate than most previous estimates. Very fast and very slow rates were encountered in different globin lineages and at different stages of descent, reducing the effectiveness of globins as molecular clocks. Rates increased with gene duplication and decreased after selection discovered useful specializations in the products of genes which had previously been freer to accept mutations. The early eutherian radiation was characterized by rapid rates of globin evolution, but the later hominoid radiation by extremely slow rates. This pattern was related to more complicated grades of internal organization evolving in human ancestors. The types of nucleotide replacements in the globin messengers over the long course of globin evolution did not seem indicative of any special mutational mechanisms.

The primary structure of L-1 light chain of chicken fast skeletal muscle myosin and its genetic implication

It is known that in general fast skeletal muscle myosin consists of 2 heavy chains and 4 light chains [ 1,2]. We have also recognized 4 components in the light chain fraction from chicken fast skeletal muscle myosin by CelIulogel electrophoresis at pH 8.3, and designated these light chains L-l, L-2, L-3 and L-4 light chains in the order of their increasing anionic mobilities [3]. L-l is also known as alkali light chain 1 (Al) and L-4 as alkali light chain 2 (A2). L-2 and L-3 are also called DTNB light chains. L-3 is a phosphorylated L-2 light chain. The primary structures of L-2 and L-4 light chains of chicken fast skeletal muscle myosin have been reported in [4,.5]. We describe here the primary structure of the L-l light chain from chicken fast skeletal muscle myosin and its genetic implication.

The L-2 light chain of chicken skeletal muscle myosin.

As with rabbit skeletal muscle myosin, four kinds of light chains may be separated from chicken skeletal muscle myosin by cellogel electrophoresis at pH 8.3. They are designated L-l, L-2, L-3 and L-4 in the order of their increasing anionic mobilities. L-1 is also known as alkali light chain 1 (A1) and L-4 as alkali light chain 2 (A2). L-2 and L-3 are also called DTNB light chain. L-3 is a phosphorylated L-2 light chain. Interest in the role of these myosin light chains in the mechanism of muscle contraction has been marked. The primary structures of L-1 and L-4 light chains of rabbit skeletal muscle myosin have been determined by Frank and Weeds [1] ; they contain 190 and 149 amino acids, respectively. The primary structure of the L-2 light chain of rabbit skeletal muscle myosin has been determined by Collins [2] and by Matsuda et al. [3]. The amino acid composition of the L-2 light chain of chicken skeletal muscle myosin has been found by Lowey and Holt [4] and its partial amino acid sequence reported by Jakes et al. [5]. We report here the primary structure of the L-2 light chain of chicken skeletal muscle myosin.

The light chains of muscle myosin: Its structure, function, and evolution

In this review I described the primary structures of myosin light chains contained in fast skeletal muscle, cardiac muscle, and gizzard muscle of chicken. In a comparison of these proteins many more amino acid substitutions than expected were recognized among the primary structures in the muscle from various organs. A fairly high homology was however shown between their primary structure, and this homology is also recognized among the light chains, parvalbumins, troponins C, and calmodulins. On the other hand, the relation between the primary structures and physiological function of these myosin light chains or the interaction between light chains and heavy chains still seems unclear. These problems are important subjects for future study.

Amino acid sequences of the cardiac L-2A, L-2B and gizzard 17 000-Mr light chains of chicken muscle myosin.

Myosins separated from various vertebrate muscles contain 2 heavy chains of -200 000-M, and 4 light chains of -20 OOOllcl, [l-4]. In connection with a relationship between the light chain structure and mechanism of the muscle contraction, we have studied the primary structures of the light chains of the fast skeletal, cardiac and gizzard muscle myosins from chicken [5-l 11. Chicken fast skeletal muscle myosin has 4 kinds of light chains designated L-l-L-4 in order of their increasing anionic mobilities at pH 8.3 [5,6,8-lo]. The L-l and L-4 light chains are also called alkali light chain 1 (Al) and alkali light chain 2 (A2), respectively. The L-2 and L-3 light chains are also known as DTNB light chains. L-3 is a phosphorylated L-2 light chain [l-3]. The primary structures of these light chains have been reported [5,6,8-lo]. Chicken cardiac muscle myosin has 2 kinds of light chains designated L-l and L-2, and the primary structure of the L-l light chain has been already reported [7,8]. We have also recognized 2 components in the L-2 light chain fraction by cellulogel electrophoresis at pH 8.3 after performic acid oxidation, and designated these components L-2A and L-2B. Chicken gizzard muscle myosin contains 2 kinds of light chains. One of them is called 20 000-M, light chain or GI light chain. It is also called regulatory light chain because it has calcium binding ability [4]. The other is called 17 000-M, light chain or GII light chain [4]. The primary structure of the 20 000-M, light chain has been reported [ 111. Here, we present the primary structures of the

Molecular Evidence for the Affinities of Tupaiidae

The basic method for deducing relationships among living organisms of any type is by assessing the degree of difference and similarity in various characters common to the groups under consideration. Traditionally, these characters have been morphological in nature. As a result, most students of systematic biology and evolution have been anatomists and paleontologists. It was largely through the efforts of these investigators that modern taxonomy has been brought to its present state. However, as is so often the case among investigators in any science, there have been disagreements both in conclusions derived from comparative work and in taxonomies developed from this work.

Evolution of the Primary Structures of Primate and Other Vertebrate Hemoglobins

Since the first living organisms appeared on the earth, the genetic information contained in genes in the form of DNA has been successfully transmitted from generation to generation, up to the present time. It is thought that these genes evolve through the process of mutation and natural selection, resulting in the diversity of organisms in the world. Assuming that the innumerable organisms now existing on the earth evolved from one source, what was the mechanism that gave rise to this diversity?

The Amino Acid Sequences of the Two Main Components of Adult Hemoglobin from Orangutan (Pongo pygmaeus)

Zusammenfassung: Die beiden Hauptkomponenten des Hämoglobins aus Orang-Utan-Blut wurden, ohne sie vorher zu trennen, vom Häm befreit; die Globine wurden dann durch Säulenchromatographie an CM-Cellulose getrennt. Dabei erhielt man zwei verschiedene erKetten (a-I, α-II) und eine ß-Kette. Die tryptischen Peptide der einzelnen 5-aminoethylierten Ketten wurden isoliert und sequenziert. Die tryptischen Peptide wurden in Homologie zur Primärstruktur des adulten Humanhämoglobins angeordnet, wodurch sich die Primärstrukturen der einzelnen Ketten ableiten ließen. Im Vergleich zum Humanhämoglobin liegen bei der a-IKette drei, bei der a-II-Kette und bei der 0-Kette je zwei Aminosäureaustausche vor; außerdem unterscheidet sich die α-1-Kette von der α-11-Kette nur durch den Austausch von Asparaginsäure gegen Glycin in Position 57.

EVOLUTION OF VERTEBRATE HEMOGLOBIN AMINO ACID SEQUENCES

ABSTRACT . The maximum parsimony method was applied to the 55 best sequenced globins to refine their sequence alignments and depict their phylogeny. Several insertions and many deletions as well as 1636 nucleotide replacements occurred in descent from the ancestral metaphyte-metazoan globin of 160 amino acid residues in a 175 position archetype alignment. Not long after, the myoglobin-hemoglobin gene duplication in primordial vertebrates homopoly-(probably tetra-) meric hemoglobin emerged. A β-α gene coding apparently for B 4 -like hemoglobin duplicated in primitive gnathostomes; and by basal amniote times, sophisticated α 2 β 2 type heterotetramers had evolved. Very fast nucleotide replacement rates in globin genes in earlier vertebrates became many times slower in amniote α and β lineages, averaging 8 to 35 times less at residue positions with the cooperative functions of heme and α 1 β 2 contacts and Bohr effect related salt bridge formation. In earlier genes for monomers which lacked cooperative behavior and especially in duplicated genes which were silent during part of their history, neutral mutations readily accumulated. This eventually facilitated the discovery by positive directional selection of specializations in α and β chains for functionally superior tetramers. Stringent selection maintained the improvements, drastically limiting types and numbers of subsequent mutations.