Liliana Milani

Mitochondria and Germ Line

Mitochondria are semi-independent organelles mostly known for their role in the energy metabolism of the eukaryotic cell. However, their function is not limited to the production of ATP; they are involved in many processes of eukaryotic life. In metazoans, mitochondria are commonly inherited uniparentally, by Strictly Maternal Inheritance (SMI), but in some bivalve molluscs two mitochondrial lineages are present: one transmitted through eggs (F-type), the other through sperm (M-type). This is the doubly uniparental inheritance of mitochondria (DUI). During the development of DUI male embryos, mitochondria coming from the spermatozoon are segregated into the forming germ line, while they are dispersed in female embryos. The molecular mechanisms beyond these segregation patterns in DUI species as well as the sex determination system in bivalves are still unknown, but this particular transmission mechanism makes of DUI an excellent model system to study mitochondrial heredity and functioning.

My research on mitochondria concerns:

Distribution and quantification of M- and F-mtDNA in gametes, embryos and adults [6, 10, 20, 28]

Ultrastructural analysis of germ line at Transmission Electron Microscopy (TEM) [9, 10]

Mitochondrial inheritance and transmission [9, 10, 39, 46]

Mitochondrial genome characterization [7, 8, 35]

Bivalve genomics and transcriptomics [12, 13, 40, 41]

Novel paternally-transmitted mitochondrial proteins [8, 16, 17, 20, 26, 29]

Role of mitochondria in germ line formation and sex-determination mechanisms [9, 12, 14, 17, 34]

Mitochondrial genome evolution [13, 21, 37, 48, 49]

Mitochondrial activity [24, 27, 38, 44, 45, 47]

Germ line differentiation and development

To understand when and how mitochondria that will be transmitted across generations are segregated to the germ line, it is fundamental to understand when and how germ cells originate. In this concern, I study germ line formation and differentiation in bivalve molluscs [25, 26, 32, 36, 42] and, more recently, I extended my research to vertebrates. Starting from an in depth analysis of oogenesis and spermatogenesis in the lizard Podarcis sicula, that allowed the description of its early germ cells and gamete differentiation [18], I documented VASA and PL10 expression pattern during gametogenesis. Both these DEAD-box proteins appear to be involved, although in different ways, in the development of P. sicula germ cells [19, 22, 33]. I am planning the same analysis in the fish Poecilia reticulata: in particular, I am working to add insights from non-model organisms on the expression of germ line determinants, since non-model organisms are important for comparative biology and evolutionary developmental biology, helping to reach a comprehensive overview on the topic.

Characterization of neurons in olfactory epithelia of vertebrates

From 2015, I am involved in the characterization of cell populations in olfactory epithelia of fish. While ciliated and microvillous olfactory sensory neurons (OSNs) are common to all vertebrates, a third group of OSNs, crypt cells, is present in bony fish, but absent in tetrapods. We approach the topic characterizing these cell populations in zebrafish and P. reticulata, since, once more, comparative studies would greatly enhance our understanding of the evolution of mechanisms of olfaction and their functioning. So far, available antibodies to target specific proteins of neuronal cells are developed in model organisms, such as mouse, rat, bovine and humans, and their specificity were not deeply tested in other organisms. Thus, their use as molecular markers for the identification of different cell types in different animals needed an in-depth validation. My first approach to this issue was indeed testing in P. reticulata several antibodies previously used in zebrafish. The first results obtained indicate a differential pattern of immunoreaction in the OSN populations of two species, suggesting caution in generalization on marker specificity in fish [31]. We also investigate the effect of copper, an ubiquitously diffusing olfactory toxicant, on the three different OSNs in zebrafish [30, 43].

Reproductive and evolutionary biology of stick insects (Insecta Phasmida)

Stick insects show noteworthy abilities to overcome species-specific reproductive isolation mechanisms by means of processes such as hybridization, polyploidy, parthenogenesis, hybridogenesis, and androgenesis. From an evolutionary standpoint, such tangled reproductive interactions can lead to the complex phyletic relationships known as “reticulate evolution”. Bacillus, Clonopsis, Leptynia, and Pijnackeria species complexes became paradigmatic of the whole array of reproductive modes. In order to address the puzzle of species complex structure and relationships, I investigated these insect species by karyology, scanning electron microscopy (SEM) of body and eggs, sequencing of mitochondrial and nuclear genes, and the modifications of meiotic division that characterize different parthenogenetic variants [1-5, 11, 15, 23, 50].

References

* Corresponding author; ** Co-first author.

1. Ghiselli F., Milani L., Scali V., Passamonti M. (2007) Molecular Ecology, 16(20):4256-4268. doi: 10.1111/j.1365-294X.2007.03471.x.
2. Milani L.*, Scali V., Passamonti M. (2009) Journal of Zoological Systematics and Evolutionary Research, 47(2):132-140. doi: 10.1111/j.1439-0469.2008.00489.x.
3. Scali V., Milani L. (2009) Italian Journal of Zoology, 76(3):291-305. doi: 10.1080/11250000802649750. [0,800]
4. Milani L., Ghiselli F., Pellecchia M., Scali V., Passamonti M. (2010) BMC Evolutionary Biology, 10:258. doi: 10.1186/1471-2148-10-258.
5. Scali V., Milani L., Passamonti M. (2010) Invertebrate Reproduction and Development, 54:143-150. doi: 10.1080/07924259.2010.9652326.
6. Ghiselli F., Milani L., Passamonti M. (2011) Molecular Biology and Evolution, 28:949-961. doi: 10.1093/molbev/msq271.
7. Passamonti M., Ricci A., Milani L., Ghiselli F. (2011) BMC Genomics, 12:442. doi: 10.1186/1471-2164-12-442.
8. Breton S., Ghiselli F., Passamonti M., Milani L., Stewart D.T., Hoeh W.R. (2011) PLoS ONE, 6(4):e19365. doi: 10.1371/journal.pone.0019365.
9. Milani L.*, Ghiselli F., Maurizii M.G., Passamonti M. (2011) PLoS ONE, 6(11):e28194. doi: 10.1371/ journal.pone.0028194.
10. Milani L.*, Ghiselli F., Passamonti M. (2012) Journal of Experimental Zoology B (Molecular and Developmental Evolution), 318:182-189. doi: 10.1002/jez.b.22004.
11. Scali V., Milani L., Passamonti M. (2012) Contributions to Zoology, 81:25-42.
12. Ghiselli F., Milani L., Chang P.L., Hedgecock D., Davis J.P., Nuzhdin S.V., Passamonti M. (2012) Molecular Biology and Evolution, 29:771-786. doi: 10.1093/molbev/msr248.
13. Ghiselli F., Milani L., Guerra D., Chang P.L., Breton S., Nuzhdin S.V., Passamonti M. (2013) Genome Biology and Evolution, 5:1535-1554. doi: 10.1093/gbe/evt112.
14. Milani L.*, Ghiselli F., Nuzhdin S.V., Passamonti M. (2013) Journal of Experimental Zoology B (Molecular and Developmental Evolution), 320B:442–454. doi: 10.1002/jez.b.22520.
15. Scali V., Milani L., Passamonti M. (2013) Journal of Zoological Systematics and Evolutionary Research, 51:213-226. doi: 10.1111/jzs.12018.
16. Milani L.*, Ghiselli F., Guerra D., Breton S., Passamonti M. (2013) Genome Biology and Evolution, 5:1408-1434. doi: 10.1093/gbe/evt101.
17. Milani L.*, Ghiselli F., Maurizii M.G., Nuzhdin S.V., Passamonti M. (2014) Genome Biology and Evolution, 6(2):391–405. doi: 10.1093/gbe/evu021.
18. Milani L.*, Maurizii M.G. (2014) Molecular Reproduction and Development, 81:777. doi: 10.1002/mrd.22348.
19. Milani L.*, Maurizii M.G. (2014) Molecular Reproduction and Development, 81:390. doi: 10.1002/mrd.22349.
20. Milani L.*, Ghiselli F., Iannello M., Passamonti M. (2014) Current Genetics, 60:163–173. doi: 10.1007/s00294-014-0420-7.
21. Breton S., Milani L.**, Ghiselli F., Guerra D., Stewart D.T., Passamonti M. (2014) Trends in Genetics, 30:555–564. doi: 10.1016/j.tig.2014.09.002.
22. Milani L.*, Maurizii M.G. (2015) Journal of Experimental Zoology B (Mol. Dev. Evol.), 324(5):424–434. doi: 10.1002/jez.b.22628.
23. Milani L.*, Scali V., Passamonti M. (2015) Journal of Zoological Systematics and Evolutionary Research, 53(2):116–123. doi: 10.1111/jzs.12087.
24. Milani L.*, Ghiselli F. (2015) Biology Direct, 10:22. doi: 10.1186/s13062-015-0057-6.
25. Milani L.*, Maurizii M.G., Pecci A., Ghiselli F., Passamonti M. (2015) Molecular Reproduction and Development, 82:406-407. doi: 10.1002/mrd.22502.
26. Milani L.*, Ghiselli F., Pecci A., Maurizii M.G., Passamonti M. (2015) PLoS ONE 10(9):e0137468. doi: 10.1371/journal.pone.0137468.
27. Milani L.* (2015) Biology Letters, 11:20150732. doi: 10.1098/rsbl.2015.0732.
28. Guerra D., Ghiselli F., Milani L., Breton S, Passamonti M. (2016) Heredity, 116:324–332. doi:10.1038/hdy.2015.105.
29. Milani L.*, Ghiselli F., Passamonti M. (2016) Current Zoology, 62(6):687–697. doi: 10.1093/cz/zow044.
30. Lazzari M., Bettini S., Milani L., Maurizii M.G., Franceschini V. (2017) Aquatic Toxicology, 183:54–62. doi: 10.1016/j.aquatox.2016.12.012.
31. Bettini S., Milani L.**, Maurizii M.G., Lazzari M., Franceschini V. (2017) Brain Structure and Function, doi: 10.1007/s00429-017-1386-2.
32. Milani L.*, Pecci A., Ghiselli F., Passamonti M., Bettini S., Franceschini V., Maurizii M.G. (2017) Histochemistry and Cell Biology, 148:157–171. doi: 10.1007/s00418-017-1560-x.
33. Milani L.*, Pecci A., Cifaldi C., Maurizii M.G. (2017) Journal of Experimental Zoology B (Molecular and Developmental Evolution) 328B:433–448. doi: 10.1002/jez.b.22744.
34. Pozzi A., Plazzi F., Milani L., Ghiselli F., Passamonti M. (2017) Molecular Biology and Evolution, 34(8):1960–1973. doi: 10.1093/molbev/msx140.
35. Ghiselli F., Milani L.**, Iannello M., Procopio E., Chang P., Nuzhdin S.V., Passamonti M. (2017) PeerJ, 5:e3692. doi: 10.7717/peerj.3692.
36. Milani L.*, Pecci A., Ghiselli F., Passamonti M., Lazzari M., Franceschini V., Maurizii M.G. (2017) Histochemistry and Cell Biology. doi: 10.1007/s00418-017-1607-z.
37. Skibinski D., Ghiselli F., Diz A., Milani L., Mullins J. (2018) Genome Biology and Evolution. doi: 10.1093/gbe/evx235
38. Ghiselli F., Breton S., Milani L.* (2018) Philosophical Transactions of the Royal Society B. Phil. Trans. R. Soc. B 373: 20170147. doi: 10.1098/rstb.2017.0147
39. Punzi E., Milani L.**, Ghiselli F., Passamonti M. (2018) Journal of Experimental Zoology B (Mol. Dev. Evol.). 330:41–51
40. Capt C., Renaut S., Ghiselli F., Milani L., Johnson N., Sietman B, Stewart D, Breton S. (2018) Genome Biology and Evolution, 10:577-590
41. Renaut S., Guerra D., Hoeh W.R., Stewart D.T., Bogan A.E., Ghiselli F., Milani L., Passamonti M., Breton S. (2018) Genome Biology and Evolution evy117. https://doi.org/10.1093/gbe/evy117
42. Reunov A., Alexandrova Y., Reunova Y., Komkova A., Milani L. (2019) Zygote, 27:25-35. https://doi.org/10.1017/S0967199418000588
43. Lazzari M., Bettini S., Milani L., Maurizii M.G., Franceschini V. (2019) Aquatic Toxicology, 206:14–23. https://doi.org/10.1016/j.aquatox.2018.10.011
44. Bettinazzi S., Rodriguez E., Milani L., Blier PU, Breton S. (2019) Proceedings of the Royal Society B, 286:20182708. http://dx.doi.org/10.1098/rspb.2018.2708
45. Havird J.C., Weaver R.J., Milani L., Ghiselli F., Greenway R., Ramsey A.J., Jimenez A.G., Dowling D.K., Hood W.R., Montooth K.L., Estes S., Schulte P.M., Sokolova I.M., Hill G.E. (2019) Integrative and Comparative Biology, 59, 856–863. doi:10.1093/icb/icz132.
46. Ghiselli F., Maurizii M.G., Reunov A., Ariño-Bassols H., Cifaldi C., Pecci A., Alexandrova Y., Bettini S., Passamonti M., Franceschini V., Milani L.* (2019) Integrative and Comparative Biology, 59,1016–1032. doi: 10.1093/icb/icz061
47. Bettinazzi S., Nadarajah S., Dalpé A., Milani L., Blier P.U., Breton S. (2020) Phil. Trans. R. Soc. B 375: 20190177. http://dx.doi.org/10.1098/rstb.2019.0177
48. Ghiselli F, Milani L. (2020) Philosophical Transactions of the Royal Society B, 375: 20190169. http://dx.doi.org/10.1098/rstb.2019.0169
49. Milani L., Ghiselli F. (2020) Philosophical Transactions of the Royal Society B, 375: 20190186. http://dx.doi.org/10.1098/rstb.2019.0186
50. Milani L.*, Scali V., Punzi E., Luchetti A., Ghiselli F. (2020) Organisms Diversity & Evolution.