terms and definitions of medaka genetics
WORK IN PROGRESS
deutschsprachiger Text: siehe unten
A
allele: describes the different varieties of a specific part of dna on homologous chromosomes
Adrianichtyidae: the order the genus Oryzias belongs to
Aplocheilus/Haplochelus: the genus medaka scientifically belonged to from 1866 to 1905
autosomes: all chromosomes which are not gonosomes
anaphase:…
B
black: see melanophore
…
C
cell: smallest living unit of an organism
chromosome: coiled dna,
chromatide: is a half of a duplicated chromatosome in metaphase
chromatophore: cell with the colouring function
colour: that is what this homepage is about
centromere: where the two homologous chromatides are connected, depending on where the centromere is, the chromosome has a different shape
D
diploid: a cell (or an individual) carrying a full (2n) set of chromosomes, meaning there are pairs of chromosomes, one set from each parent, meaning one paternal set of chromosomes and one maternal set of chromosomes
dna: Deoxyribonucleic acid. A doubled molecular chain storing the informations for the cells functioning. Contains of paired bases in a specific order and is formed as a double-helix
…
E
encoding: what a gene stands for translated in cell functioning
…
F
Fx: filial generation/offspring generation. F1 is the first offspring or filial generation after the crossing of the parental generation. F2 is the second offspring or filial generation, F3 is the third….
…
G
gene: a specified part of a dna strand encoding for one specific protein/cell function. The sequence of the dna bases are specified for each known gene.
gonosomes: chromosomes storing information for the sexual development and sexual phenotypes
genotype: …
H
haploid: a cell carrying only one set of chromosoms (n) after meiosis, normally those cells are not viable, except for cells used for reproduction, where two haploid cells merge again. This means there are no pairs of chromosomes, but only a singular set.
heterozygous: an individual (or a diploid cell) carrying two different alleles of a specific gene.
homozygous: an individual (or a diploid cell) carrying two identical alleles of a specific gene. Pure bred.
homologous: in a diploid cell each chromosom from parent A has an equivalent chromosom from parent B
homologous recombination: crossing over and exchanging parts of matching chromosomes from maternal to paternal chromosomes and vice versa
heterologous: crossing over and exchanging parts of non-matching chromosomes
I
intermediate: a phenotype laying somewhere inbetween two other phenotypes, so no dominant/recessive inheritance
J
junction: see centromer
K
…
L
locus: the specific place in a chromosome, where typically a specific gene can be found
leukophore: the white chromatophore (colour cell) with a snowflake-like pattern (dentritic shape). It contains leukosomes, which are able to spread equally in the whole cell or can be pulled together to concentrated in the cell middle. This cell type is located on top of the scales. It reflectes light and looks white or creamwhite. It lets through a little amount of light and looks brownish if watched through an transmitted light microscope. It can be seen on a good picture and also with magnificion with factor 10 to 20. (see picture in the german part)
leukosomes: contain uric acid and pterine.
M
maternal: … related to the mother animal, everything what comes from the mother animal
melanin: it’s a darkbrown to black pigment which is build up from the aminoacid tyrosine. It’s located in melanosomes and makes up the black colour. It’s absorbing light.
melanosome: little intracellular bodys in melanophores, normally filled with melanin. They are normally able to dispers equally in the whole cell and also able to be pulled back in the cell center. This movement can only be watched under a microscope.
melanophore: chromatophore which normally contain melanosomes. They are located mainly on top of the scales. They have a dentritic shaped outline and look a bit like black snowflakes. Can be identified already with a good photograph or with 10x to 20x magnificion.
meiose:…
mitose:…
metaphase:…
N
nucleolus: …
nucleoid:…
O
ovulation: …
P
paternal: … related to the father animal, everything what comes from the father animal
P: abbreviation for „parental generation“, sometimes also F0 is used isntead of P. See F.
Poecilia latipes: the first scientific name given to medaka from Coenraad Jacob Temminck and Hermann Schlegel in 1846, published in Fauna Japonica by Philipp Franz von Siebold
Poecilia: nowadays the genus where for example guppy and molly belong to.
Punnet square: a tool developed by the british geneticist Reginald Punnett to calculate the frequencies of the different genotypes of the offspring
prophase:
Q
…
R
…
S
…
T
…
U
…
V
…
W
…
X
X-chromosome: one of the genosomes regulating the sex of the individuals. A typical female has XX in the genotype
xanthophore: yellowish to orange colour cell with a dentritic cell shape (like smowflake). It contains xanthosomes and it is also able to take in additional colour pigments like betacarotinoids/asthaxathine in the cell plasma. In contrast to other fish, xanthophores in medaka are not only located on top of the scales, but also are located below and in deeper tissue. This chromatophore is smaller than melanophores and leukophores and due to its appearance in multiple layers it’s hard to see the definable cell shape in a 20x magnificion picture.
xanthosome: is a intracellular body filled with pterine and carotinoids. It absorbes light and looks yellowish to orange. They are normally able to dispers equally in the whole cell and also able to be pulled back in the cell center. This movement can only be watched under a microscope.
Y
Y-chromosome: one of the genosomes regulating the sex of the individuals. A typical male has the genotype XY
…
Z
…
Definitionen und Begriffe in der Medaka Genetik
A
Allel, allele Erbfaktoren: sind verschiedene Gene/DNA-Abschnitte die jeweils am gleichen Locus von homologen Chromosomen liegen, also sind es sich entsprechende Gene, die sich direkt beeinflussen in der Ausprägung eines Merkmales
…
B
…
C
Crossing over: Austausch von Chromosomenabschnitten homologer Chromosomen, geschieht in der Prophase 1 der Meiose
D
Desoxyribonukleinsäure, DNS: zwei Stränge, in einer Doppelhelix umeinander gewunden, die in ihrer Molekularen Reihenfolge die Erbsubstanzen/Informationen für das Funktionieren der Zellbestandteile enthält und aus einer spezifischen Reihenfolge an Basenpaaren besteht
Dominanz, dominant: das zur Ausprägung kommende Merkmal. Gegensatz zu rezessiv.
E
Epistasie, epistatisch: das Gen welches mit der Ausprägung seines Phänotypen den Phänotypen eines anderen (hypostatischen) Merkmals überlagert, was allerdings dazu kein Gegengen/Allel ist, also auf einem anderen Locus liegt. Hypostasie/Epistasie bezeichnet die Wechselwirkung von Genen die nicht direkt (z.B. dominant-rezessiv) zueinander einwirken, sondern nur im Phänotyp
…
F
F-Generation, Filialgeneration, Tochtergeneration: …
G
Gen: …
H
Hypostasie, hypostatisch: ist das in der Ausprägung seines Phänotypes von einem epistatischen Gen unterdrückte Merkmal, das allerdings dazu kein Gegengen/Allel ist, also auf einem anderen Locus liegt. Hypostasie/Epistasie bezeichnet die Wechselwirkung von Genen die nicht direkt (z.B. dominant-rezessiv) zueinander einwirken, sondern nur im Phänotyp.
homolog: gleichartige Chromosomen, im diploiden Chromosomen Satz gibt es jeweils zwei homologe Chromosomen = zwei zueinander passende Chromosomen
I
J
K
Keimzellen: Überbegriff für Eizellen und Samenzellen
L
Leukophore:
M
Melanophore:
N
O
P
Q
R
Rezessivität, rezessiv: Unterdrückung (Nicht-Ausprägung) eines Merkmales. Gegenteil von Dominanz/dominant.
Reziprozitätsregel: anderer Name für Uniformitätsregel
S
Spaltungsregel, zweite Mendelsche Regel: ….
T
Translokation: Austausch von Chromosomenabschnitten nicht-homologer/heterologee Chromosomen…
U
Uniformitätsregel, erste Mendelsche Regel: bei der Kreuzung zweier Individuen, die auch in einem Merkmal reinerbig/homozygot unterscheiden, ist die erste Tochtergeneration in Bezug auf dieses Merkmal einheitlich/uniform. Reziprozitätsregel ist ein anderer Name dafür.
Unabhängigkeitsregel, dritte Mendelsche Regel: Merkmale vererben sich unabhängig voneinander. Trifft nur zu wenn die entsprechenden Gene auf zwei verschiedenen nicht-homologen Chromosomen liegen
V
…
W
…
X
X-Chromosom: eines der beiden Geschlechtschromosomen. Normale Weibchen haben dieses homyzgot (doppelt vorliegen) also XX. Normale Männchen haben nur ein X-Chromosom und ein Y-Chromosom, also XY.
Xanthophore:
Y
Y-Chromosom: das zweite Geschlechtschromosom. Reguliert im Normalfall die Ausprägung der Männlichen Geschlechtsorgane und Phänotypmerkmale des Männchens, Genotyp: XY.
Z
…