|
|
Maternal effect in selected rodent species: positive and negative effect on offspring fitness
Malá, Jana ; Landová, Eva (advisor) ; Stopková, Romana (referee)
This work describes the most studied mechanisms which could be classified as maternal effects. Here I focus on the effects of body weight, health status, intestinal microflora and age of the mother in model rodent organisms. I also present factors such as the position of the young in the uterus, population density, stress and especially maternal care, which accompanies this entire work. Each of these mechanisms can positively or negatively influence offspring fitness, depending on specific environmental conditions. Maternal behaviour is presented here in the form of research, which documents both epigenetic and genetic influences acting on its final form. Maternal care as an element of maternal behaviour shows a different measure between individuals, indicated by the frequency of licking and cleaning offsprings. By evaluation of maternal care, we can find in laboratory populations two stable phenotypes of individuals with different behavioural manifestations in terms of sexual behaviour, stress reaction, aggression or cognitive abilities. The discussion critically evaluates whether maternal care really affects reproductive success and whether it can therefore be considered an adaptive mechanism. According to the available information, low maternal care appears to be a more beneficial strategy in...
|
|
|
Maternal effect on body size in the Madagascar ground gecko Paroedura picta
Píchová, Veronika ; Starostová, Zuzana (advisor) ; Vrtílek, Milan (referee)
The maternal effect is a phenotypic process in which the mother influences her offspring through her phenotype, her behaviour and also through the environmental condition that affect her. This non-genetic effect can have a variety of manifestations. One way that mothers of oviparous vertebrates can affect their offspring is through the size of their eggs. This thesis aims to investigate whether and how female of the gecko Paroedura picta can influence the growth and final body size of their offspring. Females of this species can reproduce at an early age and increase the size of their eggs during their lifetime. Therefore, I investigated whether this difference in energy allocation to the eggs would affect the size of the hatchlings and subsequently their growth and final body size. The result shows that the eggs mass increases with female body size and larger hatchlings were born from larger eggs. However, smaller hatchlings from smaller eggs grow faster compared to larger ones and exhibit so called compensatory growth. Only the sex affects final body size of an individual, but this effect is not apparent at hatching. In this gecko, the maternal effect is only apparent in the egg size and hatchling size but it does not affect the growth or final body size of an offspring later in the ontogeny.
|
guest ::
