Eye lens weight as an age indicator in yellow-necked mice

Nabagło, Leszek; Pachinger, Karol

doi:10.4098/at.arch.79-15

Cited by 11 publications

(7 citation statements)

References 1 publication

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“…Nevertheless, according to our results none of the three characters can be selected as age discriminant because of the high sample variability. The same problem accounts for the eye lens, even though it is considered one of the best to estimate age in other rodent species (Nabaglo and Pachinger 1979 ;Hagen et al 1980 ;Kravetz et al 1981 ;Malcom and Brooks 1981 ;Rusch et al 1982). If we had considered the growth curve for eye lens, this character would vary with age, but without any statistical support.…”

Section: Discussionmentioning

confidence: 91%

Growth and determination of age in Calomys musculinus (Rodentia, Cricetidae)

Provensal¹,

Polop²

2009

Mammalia

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Measurable characters in Calomys musculinus were selected in relation to age, in order to develop a technique for assigning individuals to age groups. Sampling was performed with laboratory specimens separated in six age groups. Eighteen cranial measurements, body length, tail length, body weight and eye lens weight were recorded for each individual and statistics of position and dispersion were calculated. A selection of characters was done, previous to two ways ANOVA (age and sex). The D2 of Mahalanobis between each pair of age groups was calculated by considering simultaneously all the characters. Discriminant functions were performed according to sex and for each age groups by using the selected characters. A significant correlation was established among age and : condylo-zygomatic length; total length of toothrow; mandible length; mandible height; zygomatic width; distance between jugular processes and nasal width. By using multivariate analysis the generalized D2 confirmed the morphological variation according to age, and the Mahalanobis D2 established that the differences were among the youngest age groups (1, 2 and 3), and between these groups and the oldest. Groups 4, 5 and 6 did not show any significant difference among them. Three different groups of Calomys musculinus were found by using the discriminant functions to classify the individuals. These groups were in accordance with the "ecological age" proposal (Crespo et al. 1970;de Villafane 1981). It is discussed the efficiency of the functions in assigning the individuals of Calomys musculinus to their corresponding biological group.Resume. -Des mensurations caracteristiques de Tage, chez Calomys musculinus, ont ete choisies chez 6 groupes de specimens de laboratoire d'äge connu. Dix-huit mensurations du crane, la longueur du corps, de la queue, le poids du corps et le poids des cristallins ont ete releves pour chaque individu et etudies statistiquement. Un choix de caracteres a ete effectue avant de realiser une ANOVA en fonction de Tage et du sexe. La distance D2 de Mahalanobis a ete calculee entre chaque paire de classes d'äge. Des fonctions discriminantes ont ete elaborees selon le sexe pour chaque groupe d'äge d'apres les caracteres choisis. Une correlation significative a ete etablie entre, d'une part, Tage et, d'autre part, la longueur condylo-basale, la longueur de la rangee dentaire, la longueur de la mandibule, la largeur zygomatique, la distance entre les processus jugulaires et la largeur nasale.Par 1'analyse multivariee, le test D2 generalise a confirme la variation de la morphologic selon Tage et le test D2 de Mahalanobis a etabli qu'il y avail des differences entre les groupes d'äge les plus jeunes (1, 2 et 3) et entre ces groupes d'äge et les plus vieux. Les groupes 4, 5 et 6 Mammalia, t. 57, n° 2,1993. Brought to you by | New York University Bobst Library Technical Serv Authenticated Download Date | 6/11/15 9:28 PM 246 MAMMALIA ne montrent aucune difference significative entre eux. Trois groupes differents de C. mnsculinns ont ete...

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Section: Discussionmentioning

confidence: 91%

Growth and determination of age in Calomys musculinus (Rodentia, Cricetidae)

Provensal¹,

Polop²

2009

Mammalia

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“…At each locality, trapping was carried out for three nights using Longworth traps provided with hay and cereals. The age of each individual was estimated from dry eye lens weight (Nabagło and Pachinger, 1979). Following dissection, the chromosomes of each mouse were prepared directly from bone marrow cells using standard techniques (Hsu and Patton, 1969).…”

Section: Methodsmentioning

confidence: 99%

Host B chromosomes as potential sex ratio distorters of intestinal nematode infrapopulations in the yellow-necked mouse (Apodemus flavicollis)

et al. 2018

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The yellow-necked mouse, Apodemus flavicollis, can be considered as a model for genetic polymorphism produced by the frequent presence of supernumerary or B chromosomes (Bs). Host genetic background is rarely taken into account in studies of parasite sex ratio. The main aim of this study was to investigate the range of infrapopulation sex ratios for nematode parasites of the yellow-necked mouse and to determine which factors most influence variation in parasite sex ratios. Six nematode species found in the collected yellow-necked mice were analysed. We confirmed the predominant pattern of female-biased sex ratios in vertebrate parasite infrapopulations. The presence of B chromosomes in host genomes played an important role in infrapopulations of Heligmosomoides polygyrus, Syphacia stroma and Trichuris muris, as hosts with B chromosomes carried a higher proportion of males. The relative increase of males in infrapopulations could result from a shift in parasite life history strategy, induced by adaptation to the specific host genotypes (Bs present). In a meta-analysis with previously published data, the sex determination system was demonstrated to play a significant role in nematode sex ratio variation, as well as specific life history patterns, such as the place of egg hatching.

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“…Biometric data (body and tail length, body mass) were collected for all captured mice. In addition, host age was determined based on dry eye lens weight (Nabaglo & Pachinger, 1979).…”

Section: Methodsmentioning

confidence: 99%

Is there a host sex bias in intestinal nematode parasitism of the yellow-necked mouse (Apodemus flavicollis) at Obedska bara pond, Serbia?

et al. 2018

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SummaryFifty-one yellow-necked mice from the Obedska bara locality were analysed for the presence of intestinal nematode parasites in order to assert whether there was a host sex bias in infection. Previous research indicated that males would be the more infected sex, either due to the immunosuppressive effect of testosterone or their different allocation of resources towards immune defence. Quantitative infection parameters were compared between host sexes for all nematode species and nematodes in general. In addition, the influence of host sex, age, total body length, body mass and presence of other nematode species on parasite abundance was analysed. No statistically significant differences between males and females were noted for any of the studied quantitative parameters, leading to an absence of sex-biased parasitism in this study.

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Eye lens weight as an age indicator in yellow-necked mice

Cited by 11 publications

References 1 publication

Growth and determination of age in Calomys musculinus (Rodentia, Cricetidae)

Growth and determination of age in Calomys musculinus (Rodentia, Cricetidae)

Host B chromosomes as potential sex ratio distorters of intestinal nematode infrapopulations in the yellow-necked mouse (Apodemus flavicollis)

Is there a host sex bias in intestinal nematode parasitism of the yellow-necked mouse (Apodemus flavicollis) at Obedska bara pond, Serbia?

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