Department of Psychology and Neuroscience, Baylor University, Waco, Texas.
Institute of Biomedical Studies, Baylor University, Waco, Texas.
Genes Brain Behav. 2020 Feb;19(2):e12611. doi: 10.1111/gbb.12611. Epub 2019 Nov 1.
There have been several reports that individuals with Fragile X syndrome (FXS) and animal models of FXS have communication deficits. The present study utilized two different call classification taxonomies to examine the sex-specificity of ultrasonic vocalization (USV) production on postnatal day (PD8) in the FVB strain of Fmr1 knockout (KO) mice. One classification protocol requires the investigator to score each call by hand, while the other protocol uses an automated algorithm. Results using the hand-scoring protocol indicated that male Fmr1 KO mice exhibited longer calls (P = .03) than wild types on PD8. Male KOs also produced fewer complex, composite, downward, short and two-syllable call-types, as well as more frequency steps and chevron call-types. Female heterozygotes exhibited no significant changes in acoustic or temporal aspects of calls, yet showed significant changes in call-type production proportions across two different classification taxonomies (P < .001). They exhibited increased production of harmonic and frequency steps calls, as well as fewer chevron, downward and short calls. According to the second high-throughput analysis, female heterozygotes produced significantly fewer single-type and more multiple-type syllables, unlike male KOs that showed no changes in these aspects of syllable production. Finally, we correlated both scoring methods and found a high level of correlation between the two methods. These results contribute further knowledge of sex differences in USV calling behavior for Fmr1 heterozygote and KO mice and provide a foundation for the use of high-throughput analysis of neonatal USVs.
已有多项研究报告指出脆性 X 综合征（FXS）患者和 FXS 动物模型存在沟通障碍。本研究采用两种不同的叫声分类法，以研究 Fmr1 敲除（KO）小鼠在产后第 8 天（PD8）时，雄性和雌性 Fmr1 敲除（KO）小鼠超声发声（USV）的产生是否存在性别特异性。一种分类方案要求研究人员手动为每个叫声打分，而另一种方案则使用自动算法。使用手动评分方案的结果表明，雄性 Fmr1 KO 小鼠在 PD8 时的叫声持续时间更长（P =.03）。雄性 KO 还产生了较少的复杂、复合、向下、短和双音节叫声类型，以及更多的频率步和人字形叫声类型。雌性杂合子在叫声的声学或时间方面没有表现出显著变化，但在两种不同的分类分类法中，叫声类型的产生比例发生了显著变化（P <.001）。它们表现出更多的谐波和频率步叫声，以及更少的人字形、向下和短叫声。根据第二种高通量分析，雌性杂合子产生的单音节和多音节的数量明显减少，而雄性 KO 则在这些音节产生方面没有变化。最后，我们对两种评分方法进行了相关性分析，发现两种方法之间具有高度相关性。这些结果进一步揭示了 Fmr1 杂合子和 KO 小鼠在 USV 叫声行为上的性别差异，并为新生儿 USV 的高通量分析提供了基础。
