Complex sentence: What may be transmitted in such a case are RNA's including piRNAs, siRNAs, miRNAs or other regulatory RNAs that packaged in egg or sperm cause paramutation on transmission to the next generation.
Split into simpler sentences: What may be transmitted in such a case are RNA's such as piRNAs, siRNAs, miRNAs or other regulatory RNAs. These are packaged in egg or sperm and cause paramutation upon transmission to the next generation.