Expression Of Palmdelphin Gene During Postnatal Development Of Rat Cerebellum

Cerebellum,as he center of accommodation for the coordination and control of voluntary movement in the central neural system, is the model of motor learning.Cerebellar development is long-term process, including stages of the prenatal and postnatal development. Notably, three weeks after birth is the important stage for the formation of certain innervations and also the axogenesis and dentritogenesis of purkinje neuron.In our previous study, the functional associated protein of Metastasis suppressor 1 (Mtss1) in the in the rat cerebellar post-development have been screened by IMD-domain pull down assay followed with mass spectrometry. As the result, palmdelphin, abbreviated as PalmD, has been identified as one of most promising candidates.It has been reported that PalmD belongs to paralemmin family. Most of paralemmin family members have been implicated in the plasma membrane dynamics and cell shape control. A representative protein paralemmin is majorly located in the axon, dentrite and spine. As an exception, PalmD is mainly distributed in cytosol and devoid of functional reports.To explore the relativity of PalmD and Mtss1 in the cerebellar development, in situ hybridization (ISH) has been used to study the tempo-spatial pattern of PalmD in the postnatal development stage. ISH is a type of hybridization that uses a labeled complementary DNA or RNA probe to localize a specific DNA or RNA sequence in the section of tissue qualitatively and/or quantitatively. In our study, cerebellum tissue sections of postnatal 0,7,14,21 days and 56 days have been hybridized with the digoxin-labeled RNA probe. The staining pattern indicated that PalmD has a transient expression peak at postnatal 7 days whereas the signal on other stages remains undetected. Additionally, the obvious signals of PalmD were focused on the internal granule cell layer, especially purkinje neuron. In consideration of the functional character of paralemmin family and the structural motif analysis of PalmD, these results strongly implicated that PalmD may functioned in the postnatal neural morphogenesis of cerebellum. Furthermore, the distribution pattern of PalmD is similar to that of Mtss1, supporting our previous assumption that PalmD and Mtss1 may collaborated in the postnatal development.To further examine the relativity between transcription level of PalmD and cerebellar postnatal development quantitatively, semi-quantitative RT-PCR has been applied in the study. The result confirmed the data from ISH that there was an expression peak of PalmD at postnatal 7 day.In summary, this work is the further exploration of our previous study. Importantly, this study firstly showed that PalmD is a cerebellum postnatal development related gene, most probably involved in the morphogenesis of purkinje neuron. Its expression pattern was in accordance with our previous prediction that it may functionally associated with Mtss1 in the neural development of cerebellum. In addition, the cloning of full-length PalmD will be helpful for the future study on the cellular function of PalmD and its\interaction with Mtss1.