magistrsko delo
Maja Belič (Author), Tina Klenovšek (Mentor), Boris Kryštufek (Co-mentor)

Abstract

Analizirali smo modularno organizacijo spodnje čeljustnice velikega hrčka (Cricetus cricetus) z vidika ontogenetskega razvoja in spolnega dimorfizma. V vzorcu 118 živali so bili osebki obeh spolov, stari od 30 dni do 4 let, razdeljeni v 10 starostnih razredov. Samci so imeli večje spodnje čeljustnice od samic, pri čemer so se statistično značilne razlike pojavile pri 120. dnevu starosti. Oblika čeljustnice se je spreminjala skladno z rastjo, spolni dimorfizem pa je bil s starostjo osebkov izrazitejši. Razlike med spoloma v obliki spodnje čeljustnice so se pojavile s 150. dnem starosti. Delitev spodnje čeljustnice na dva hipotetična modula, na čeljustno telo in čeljustno vejo, smo najprej testirali ločeno za mlade (30 – 150 dni) in odrasle (2. – 4. leto življenja) osebke, delitve pa nismo potrdili. Ob natančnejši analizi starostnih razredov je bila modularna delitev statistično značilna tako pri mladih (40 – 50 dni) kot mladostnih osebkih (90 – 120 dni). Osebke od 150. dneva starosti dalje smo testirali tudi ločeno glede na spol. Delitev na dva modula je bila statistično značilna le pri odraslih samicah (2. – 4. leto življenja). Pri samcih hipoteza o modularnosti ni bila potrjena. Hipotezo modularne organizacije spodnje čeljustnice smo testirali tudi po izločitvi vpliva alometrije in jo potrdili pri mladih osebkih (30 – 150 dni), pri odraslih pa ne. Zaključimo lahko, da je modularna organizacija spodnje čeljustnice pri velikem hrčku bolj izrazita pri mladih kot odraslih živalih, kar je v nasprotju s pričakovanji, da imajo mlade živali strukturno manj integrirano lobanjo od odraslih živalih. Pri odraslih živalih pričakujemo izoblikovane funkcionalne module, ki se pri mladih živalih še razvijajo. Pri velikem hrčku na modularno organizacijo lobanje vplivata tudi alometrija in spolni dimorfizem.

Keywords

magistrska dela;spodnja čeljustnica;veliki hrček;ontogenija;modularnost;alometrija;spolni dimorfizem;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FNM - Faculty of Natural Sciences and Mathematics
Publisher: [M. Belič]
UDC: 599.323.51(043.2)
COBISS: 208277507 Link will open in a new window
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Other data

Secondary language: English
Secondary title: Ontogenetic perspective of modular organization of mandible of common hamster, Cricetus cricetus (Linnaeus,1758)
Secondary abstract: We analyzed the modular organization of the mandible in the common hamster (Cricetus cricetus), focusing on ontogeny and sexual dimorphism. Our study included 118 individuals, aged 30 days to 4 years, divided into 10 age groups. Males had larger mandibles than females, with statistically significant differences becoming evident at 120 days of age. Mandible shape changed with growth, and sexual dimorphism became more pronounced with age, particularly after 150 days. We tested the hypothesis that the mandible consists of two hypothetical modules, the alveolar region and the ascending ramus, in both young (30 - 150 days) and adult (2 - 4 years) specimens. While the overall hypothesis was not confirmed, a detailed analysis of age groups revealed significant modularity in juvenile (40 - 50 days) and subadult (90 - 120 days) specimens. After 150 days of age, the sexes were tested separately. Modularity was significant only in adult females (2 - 4 years) but not in males. We also tested the hypothesis of modular organization of the mandible after removing the effects of allometry. Modularity was confirmed in young individuals (30 - 150 days) but not in adults. Our results suggest that mandible modularity is more pronounced in young individuals of the common hamster, contrary to expectations that younger animals have less integrated cranial structures than adults. In adults, distinct functional modules are expected to be fully developed, while in young animals, they are still developing. In the common hamster, mandible modularity is influenced by allometry and sexual dimorphism, among other factors.
Secondary keywords: master theses;mandible;common hamster;ontogeny;modularity;allometry;sexual dimorphism;Veliki hrček (vrsta);Mandibula;Univerzitetna in visokošolska dela;
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za naravoslovje in matematiko, Oddelek za biologijo
Pages: IX, 55 f.
ID: 24904937