雌の宿主特異種である普通カクヨウの遺伝的証拠
H L Gibbs1, M D Sorenson, K Marchetti
1Department of Biology, McMaster University, Hamilton, Ontario, Canada. gibbs@mcmaster.ca
Nature
|September 23, 2000
まとめ
コモンカクウ (Cuculus canorus) の宿主種族は,雌の系統の専門化により,区別され続けています. 遺伝子解析はミトコンドリアDNAの違いを明らかにするが,核DNAの変異は明らかにせず,女性特有の宿主適応を支持している.
科学分野:
- 進化生物学の進化生物学について
- 鳥類学 鳥類学とは,鳥類学である.
- 行動生態学 行動生態学
背景:
- コモンカク (Cuculus canorus) は宿主特異的な種族 (gentes) を表している.
- それぞれの種族は,宿主種に匹敵する独特の卵を産み,生殖分離についての疑問を投げかけます.
- これらのゲンテスの遺伝的基盤を理解することは,進化論の研究にとって極めて重要です.
研究 の 目的:
- 共通カクヨウの異なる宿主種族を維持する遺伝的メカニズムを調査する.
- ゲンテスとその継承方式の間に遺伝的差異があるかどうかを判断する.
- 遺伝的発見と観察された女性特有の宿主特異性を関連付ける.
主な方法:
- 異なるカクヨウ族の母性遺伝型ミトコンドリアDNA (mtDNA) の分析.
- 遺伝的多様性を評価するために,核DNAマイクロサテライトロシの分析.
- 宿主特異的適応に関する既存の行動的証拠と遺伝子データの比較.
主要な成果:
- キューコウ族の間のミトコンドリアDNAで有意な差異が見られた.
- 核DNAのマイクロサテライトロシエーションにおいて,有意な差異は観察されなかった.
- 結果は,女性系統の制限と特性の母性継承の仮説を裏付けている.
結論:
- 常見のカクヨウ族は,主に雌の系統を通して維持され,雄が遺伝子の流れを促進します.
- 潜在的にW性染色体と関連している特性の母性遺伝は,卵型特異化を引き起こす可能性が高い.
- この発見は,宿主交換とカカカカの種種の多重起源の理論を裏付けている.
関連する概念動画
Chromosomal Theory of Inheritance
In 1866, Gregor Mendel published the results of his pea plant breeding experiments, providing evidence for predictable patterns in the inheritance of physical characteristics. The significance of his findings was not immediately recognized. In fact, the existence of genes was unknown at the time. Mendel referred to hereditary units as “factors.”
Genetics of Speciation
Speciation is the evolutionary process resulting in the formation of new, distinct species—groups of reproductively isolated populations.
Hybrid Zones
Hybrid zones are narrow regions where two closely related species interact, mate, and produce hybrids. Relative to either parent species, hybrids may possess distinct phenotypic or genetic differences that impact their survival and reproductive success. The genetic variances introduced by hybridization influence species diversity and speciation processes within the hybrid zone.
Background and Environment Affect Phenotype
Although the genetic makeup of an organism plays a major role in determining the phenotype, there are also several environmental factors, such as temperature, oxygen availability, presence of mutagens, that can alter an organism’s phenotype.
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
X and Y Chromosomes
Among mammals, the gender of an organism is determined by the sex chromosomes. Humans have two sex chromosomes, X and Y. Every human diploid cell has 22 pairs of autosomes and one pair of sex chromosomes. A human female has two X chromosomes, while a male has one X chromosome and one Y chromosome.
The germline cells such as egg and sperm cells carry only half the number of chromosomes, i.e., 22 autosomes and one sex chromosome. All eggs have an X chromosome, while sperm cells can carry an X or...
The germline cells such as egg and sperm cells carry only half the number of chromosomes, i.e., 22 autosomes and one sex chromosome. All eggs have an X chromosome, while sperm cells can carry an X or...
The Ratio of X Chromosome to Autosomes
In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies.
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...


