Martina Bleyer

Dr. Martina Bleyer

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Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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SSShuwen Shan
Shuwen Shan
FXFangzheng Xu
Fangzheng Xu
MBMartina Bleyer
Martina Bleyer
SBSvenja Becker
Svenja Becker
TMTorben Melbaum
Torben Melbaum
BBBertram Brenig
Bertram Brenig
We have identified a Holstein sire named Tarantino who had been approved for artificial insemination that is based on normal semen characteristics (i.e., morphology, thermoresistance, motility, sperm concentration), but had no progeny after 412 first inseminations, resulting in a non-return rate (NRdev) of −29. Using whole genome association analysis and next generation sequencing, an associated nonsense variant in the α/β-hydrolase domain-containing 16B gene (ABHD16B) on bovine chromosome 13 was identified. The frequency of the mutant allele in the German Holstein population was determined to be 0.0018 in 222,645 investigated cattle specimens. The mutant allele was traced back to Whirlhill Kingpin (bornFeb. 13th, 1959) as potential founder. The expression of ABHD16B was detected by Western blotting and immunohistochemistry in testis and epididymis of control bulls. A lipidome comparison of the plasma membrane of fresh semen from carriers and controls showed significant differences in the concentration of phosphatidylcholine (PC), diacylglycerol (DAG), ceramide (Cer), sphingomyelin (SM), and phosphatidylcholine (-ether) (PC O-), indicating that ABHD16B plays a role in lipid biosynthesis. The altered lipid contents may explain the reduced fertilization ability of mutated sperms.

1 March 2017 in Primate Biology
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MBMartina Bleyer
Martina Bleyer
MKMarius Kunze
Marius Kunze
EGEva Gruber-Dujardin
Eva Gruber-Dujardin
KMKerstin Mätz-Rensing
Kerstin Mätz-Rensing
Data on spontaneous pathology are substantially scarce for common marmosets, compared to other laboratory animals, but is essential for the interpretation of histological findings in the context of toxicological and experimental studies. Especially if common marmosets are used as experimental animals in respiratory research, detailed knowledge on the spectrum, occurrence, and incidence of spontaneous histopathological pulmonary lesions in this non-human primate species is required. In this study, lung tissue of 638 common marmosets from the marmoset colony of the German Primate Center was examined histologically. The analysis revealed a high incidence of predominantly mild and multifocal interstitial pneumonia (32.99 %) of unknown etiology in most cases. Only few marmosets exhibited lobar pneumonia (1.41 %) and bronchopneumonia (0.94), which were mainly caused by bacterial pathogens such as Bordetella bronchiseptica and Klebsiella pneumoniae. Lung immaturity and atelectasis were common histological findings in newborn marmosets. Typical background lesions included anthracosis (8.15 %), hemosiderosis (1.72 %), extramedullary hematopoiesis (11.6 %), mineralization (10.97 %), and inflammatory cell foci (10.34 %). In addition, three cases of pulmonary arteriopathy (0.47 %) and 1 case of foreign-body granuloma (0.16 %) were detected in the marmoset study cohort. The high prevalence of circulatory disturbances (congestion, edema, hemorrhage) and changes in air content (secondary atelectasis, alveolar emphysema) could partly be explained by euthanasia-related artifacts or agonal changes. The present study provides a comprehensive overview of the range and incidence of spontaneous pulmonary histopathology in common marmosets, serving as valuable reference data for the interpretation of lung lesions in toxicological and experimental marmoset studies.

29 August 2013 in Journal of Medical Primatology
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RHRebecca Hoffmann
Rebecca Hoffmann
ABArmin Braun
Armin Braun
SKSascha Knauf
Sascha Knauf
FKFranz‐Josef Kaup
Franz‐Josef Kaup
MBMartina Bleyer
Martina Bleyer

1 June 2018 in Journal of Zoo and Wildlife Medicine
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MBMartina Bleyer
Martina Bleyer
TRTina Risch
Tina Risch
CRChristian Roos
Christian Roos
FKFranz-Josef Kaup
Franz-Josef Kaup
KMKerstin Mätz-Rensing
Kerstin Mätz-Rensing
A captive-born adult female Nilgiri langur (Semnopithecus johnii) developed an edematous swelling of the left thigh and a firm mass around the right ankle joint. The animal also suffered from lethargy and anorexia and was euthanized because of poor general condition. Necropsy revealed that the skeletal muscle of the left thigh had been replaced by a multilocular cystic mass containing numerous sand-grain–sized whitish structures. Small cysts were also present in the lung and the myocardium. The mass of the right ankle joint was histologically consistent with a myxosarcoma. In contrast, the cystic masses from the left thigh, the lung, and the myocardium represented metacestode tissue with evidence of numerous larval cestodes consistent with cysticerci. Cysticerci showed morphological characteristics of Cysticercus longicollis, the larval form of Taenia crassiceps, which was confirmed by genetic analysis. This is the first documented case of a Taenia crassiceps cysticercosis in an Old World monkey species.

9 December 2025 in EMBO Molecular Medicine
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LRLennart Roos
Lennart Roos
AGAida Garrido-Charles
Aida Garrido-Charles
NANiels Albrecht
Niels Albrecht
AVAnna Vavakou
Anna Vavakou
AAAlexey Alekseev
Alexey Alekseev
TMThomas Mager
Thomas Mager
Optogenetics allows versatile control of excitable cell networks, which advances basic science research and drives the development of future medical applications. Fast-closing channelrhodopsins (ChRs) are required for high temporal fidelity of neurostimulation, but their short channel open times require sufficient plasma membrane expression and high light intensity, challenging clinical translation. Here, we addressed the need of high-rate neurostimulation by engineering optimized blue-light-sensitive ChR variants. In particular, we report on the ChR2 variant f-ChR2 TC enabling high frequency stimulation at low light requirements, due to its good plasma membrane targeted expression and balanced closing kinetics. Upon Adeno-associated virus (AAV) mediated f-ChR2 TC expression in spiral ganglion neurons of the inner ear in mice, f-ChR2 TC accordingly enabled optogenetic stimulation of the auditory nerve with sizeable responses beyond 300 Hz and low pulse energy thresholds. Translating the approach to the larger cochlea of gerbils, we tested the utility of f-ChR2 TC for evaluating multichannel optical cochlear implants with blue light emitting diodes and found light-efficient stimulation of the auditory pathway by single LEDs at rates ≥100 Hz.

25 January 2013 in Journal of Medical Primatology
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VSVictoria Seidel
Victoria Seidel
RHRebecca Hoffmann
Rebecca Hoffmann
ABArmin Braun
Armin Braun
SSSophie Seehase
Sophie Seehase
SKSascha Knauf
Sascha Knauf
MBMartina Bleyer
Martina Bleyer