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The role of LINC complex in male germinal cells
Kmoníčková, Věra ; Komrsková, Kateřina (advisor) ; Knop, Filip (referee)
LINC (linker of the nucleoskeleton and cytoskeleton) complex is substantial for the overall function of any nuclear cell. It is a bridge between the cytoplasmic and nuclear structures which mediates transmission of mechanical forces generated on the cytoplasmic side. The main objective of this thesis is the function of distinct variants of the LINC complexes in mammalian male germinal cells throughout their development. The nuclear facing side of the LINC complex is a key player in homolog pairing and rapid chromosome movements during meiosis. The cytoplasmic facing side is necessary for the sperm head formation, proper acrosome and nucleus attachment. Evenly, another complex is essential for the head-to-tail coupling as without this one the sperm cells are found decapitated. If the subunits of the LINC complex are defective, males are afflicted with different kinds of infertilities, which nowadays is one of the important issues of our society. Many things about the role and structure of the LINC complex has been discovered due to modern technologies. These up to date findings are summarized and discussed on the following pages.
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The mechanism of impaired formation of head-tail coupling apparatus in centrobin deficient acephalic spermatozoa
Vlčková, Monika ; Frolíková, Michaela (advisor) ; Krejčová, Tereza (referee)
Acephalic sperm syndrome (ASS) is a rare form of teratozoospermia that is probably genetic in origin. The sperm of individuals with this syndrome have a damaged apparatus connecting the head and flagellum (HTCA), which leads to the formation of acephalic sperm, i.e. sperm with separate heads from flagella. Individuals affected by ASS are almost exclusively infertile. One of the proteins whose mutation causes ASS is SUN5. Together with KASH proteins, SUN proteins are part of the so-called LINC complex, which ensures the connection of the nucleoskeleton with the cytoskeleton. Centrobin is a protein involved in centriole duplication and assembly of the dividing spindle. Rats carrying a defective gene for centrobin have reduced fertility and exhibit an ASS phenotype. For that reason, this model organism was used in this work to study the possible interrelationships of proteins involved in the formation of ASS. Given the similar phenotype of centrobin and SUN5 mutated spermatozoa, there is a possibility that centrobin interacts with one of the LINC complex proteins and together they participate in the formation of the head-flagella junction. Sperm from rats with a defective centrobin gene also show significant damage to the flagella. Decreased Odf1 protein expression has previously been reported in ASS...
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The role of LINC complex in male germinal cells
Kmoníčková, Věra ; Komrsková, Kateřina (advisor) ; Knop, Filip (referee)
LINC (linker of the nucleoskeleton and cytoskeleton) complex is substantial for the overall function of any nuclear cell. It is a bridge between the cytoplasmic and nuclear structures which mediates transmission of mechanical forces generated on the cytoplasmic side. The main objective of this thesis is the function of distinct variants of the LINC complexes in mammalian male germinal cells throughout their development. The nuclear facing side of the LINC complex is a key player in homolog pairing and rapid chromosome movements during meiosis. The cytoplasmic facing side is necessary for the sperm head formation, proper acrosome and nucleus attachment. Evenly, another complex is essential for the head-to-tail coupling as without this one the sperm cells are found decapitated. If the subunits of the LINC complex are defective, males are afflicted with different kinds of infertilities, which nowadays is one of the important issues of our society. Many things about the role and structure of the LINC complex has been discovered due to modern technologies. These up to date findings are summarized and discussed on the following pages.
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